If you are in the market for antiques this winter season, you should be aware that ''buy American'' is apparently the strongest buying trend today, with English antiques in second place and all categories of Chinese works of art, from ceramics to paintings to furniture, gaining steadily in demand.
You should also be aware that the state of the general economy is having its effect on the $8.7 billion art and antiques market in the United States. This retail turnover estimate, for the year ending July 1, 1981, comes from Gray Boone, publisher of Antique Monthly magazine, who says: ''The market is definitely changing and fluctuating. The general enthusiasm has diminished across the board, which is a reaction that comes with every recession-depression. Yet things of top quality continue to command top prices, while the middle range of mediocre-quality objects are now lower in price.''
''Yes,'' confirms C. Hugh Hildesley, a senior vice-president at Sotheby's auction house in Manhattan, ''the middle of the market is shaking out, right across all categories, and speculators are getting out.'' He says, however, that despite current economic difficulties throughout the world, areas of the art market that have maintained auction popularity this season include all categories of Americana, from furniture to decorations, paintings, and prints. American impressionist paintings, as well as folk art, did extremely well, he reports, while sales of American Victoriana remained steady.
While Business Week magazine reports that its survey of auction, dealer, and private estate sales ''shows lackluster demand for many items and some sharply depressed prices as well as collector resistance to the pinnacle pricing of 1979 and 1980,'' Elizabeth Shaw of Christie's auction gallery in New York argues discreetly that ''the market is definitely more selective. We are cautious but optimistic for 1982, and are trying to emphasize better quality. When we get top material, it brings top prices, as witness the 18th-century Queen Anne secretary desk which recently brought $860,000. It had belonged to Queen Mary and to the Duke of Windsor and was in beautiful condition.''
Miss Shaw contends that there are lots of good buys right now in American Empire and Federal furniture, as well in l8th-century English silver, 17th- and early 18th-century English oak furniture, and in English portraits. ''We see all American paintings doing extremely well,'' she says, ''as well as American drawings, prints, and watercolors. Books, both antique and 20th-century first editions in pristine condition, are enjoying a strong market. And we saw a record-breaking sale of American pewter this past year.''
Terry Kovel, co-author with her husband of such books as Kovels' ''Know Your Collectibles'' and Kovels' ''Know Your Antiques,'' agrees with many other bellwethers in the field that investors, and particularly speculators, are getting out of the art and antiques market, and that bona fide collectors are feeling more comfortable once again. ''This means,'' she says, ''that things are being bought more intelligently, and prices will make much more sense and stop escalating up and down like a yo-yo.''
Mrs. Kovel contends that people, especially young couples, have grown to love old things and will continue to buy and enjoy them. So the bottom is certainly not going to drop out of the antiques and collectibles market. In her area of the Midwest, she finds big interest in such collectibles as late 19th- and early 20th- century American oak furniture, Victorian furnishings (including ''Renaissance Gothic stuff''), and American dinnerware of the 1930s such as Fiesta, Harlequin, and Autumn Leaf patterns. ''Collectors here tend to give status to old things that have utilitarian value, whether they be old dishes, glass, old lace curtains, or old clothes.''
Meanwhile, what one expert terms ''serious antique people'' or those who collect the finest of objects will discover the usual array of such treasures at the prestigious Winter Antiques Show, to be held Jan. 23-31 at the Seventh Regiment Armory in Manhattan. Many of the 75 top dealers to be represented in the show indicated they had done excellent business in 1981 and expect to do the same in 1982.
Malcolm Franklin, a Chicago dealer who specializes in English furnishings, says that his market for fine English walnut pieces made between 1690 and 1730 was excellent in both the recent Houston and Los Angeles shows, and that 17 th-century English oak is sought by his customers everywhere. Mr. Franklin says he is making fewer buying trips to England and is instead buying most of his stock from US dealers, auctions, and estates and from customers who are now selling back to him items they have purchased from him over the past 35 years.
Lallie Wigington of Linlo House in New York still returns to England several times a year to find her own homey mix of English furnishings, though admitting that her sources have far less to offer. ''Prices go up,'' she says, ''but people continue to buy good English things and to think of antiques as wise investments.''
Mario Buatta, the New York interior designer who is also chairman of the Winter Antiques Show, says: ''Most of my clients continue to buy 'blue chip antiques,' because they can live with them and enjoy them while the pieces are gradually appreciating in value. If there is any resistance, it isn't to price, but to furnishings that are merely decorative and that they do not perceive as having lasting value.''
Dealers in top Americana at the show include Thomas K. Woodard, who claims that although there is no slackening in demand for good quilts, he is taking care to present many quilts at this show in the moderate range of $350 to $1,000 . ''I don't see people rushing in the door and spending huge amounts of money anymore,'' he says. ''They are being far more careful in what they buy, and I intend to concern myself with them.''
Ed Clerk of Bethlehem, Conn., will be there with his collection of fine Shaker antiques - and may benefit from the recent upsurge of interest in all things made by the Shaker sect. Fine American and English antiques will predominate, according to show manager Russell Carrell, but people looking for Oriental rugs and porcelains, and continental furnishings, will find great choices. Prices at the show will be consistent with the quality shown, which means high in most cases.
As usual the receipts from the opening gala reception and the $5 admission fees will benefit the East Side House Settlement in New York. Running simultaneously with the Winter Antiques Show will be the Eighth Annual World Antiques Marketing Conference, to be held Jan. 24-26 at the Pierre Hotel and sponsored by Gray Boone and Antique Monthly. Mrs. Boone insists that what is happening to the market is healthy, that roller-coaster prices and false values will tend to diminish, and that collectors who know what they are doing will quietly claim their place once more.