At a time when Sino-Japanese relations are generally warm, China has warned of a possible revival of Japanese militarism. It is the first attack of this kind since the textbook controversy a year ago.
(The textbook controversy refers to the uproar generated last year throughout East Asian countries invaded by Japan during World War II when the Ministry of Education ordered the toning down of expressions in history textbooks indicating that Japan had been an aggressor or an invader.)
A commentary in the official Xinhua news agency Aug. 20 cited four items as evidence of an ''adverse current'' in Japanese politics.
* The movement to revise Japan's Constitution banning resort to war ''has become rather conspicuous this year,'' within the ruling Liberal Democratic Party.
* Fifteen members of Japan's Cabinet headed by Premier Yasuhiro Nakasone ''paid homage to those who died in aggressive wars at the Yasukuni shrine on Aug. 15.''
* ''Japan has for the first time made clear its intention to become a big political power to replace its present status as an economic power only.''
* Disregarding the commitment to Japan's peace constitution and the principle of restricting arms exports, Japan decided this year to provide the United States with military technology. Orders for arms export in 1982 amounted to 1, 100 billion Japanese yen ($45.8 million) a sharp increase of 48.6 percent over the previous year.
The Aug. 20 article did not attack Nakasone by name. But an Aug. 18 article noted his presence at the Yasukuni shrine, which is dedicated to Japan's war dead. Observers of Sino-Japanese relations do not believe the two articles indicate the start of a campaign either against Nakasone or against the buildup of Japan's defense.
Rather, the two articles, particularly the second, are taken as a warning that China will not unconditionally support the expansion of Japan's Self-Defense Force, an expansion the Reagan administration has been urging. China has thus added its voice to those of Southeast Asian nations who agree that Japan requires some defensive power but who are apprehensive lest their former invader again turn into a major military power.
''The people of various countries in Asia and the Pacific region, including the Chinese, have never forgotten the sufferings brought to them by Japanese militarism in the past,'' the Aug. 20 commentary said. ''They are closely following the development in Japan. They would feel worried about any symptom of a revival of militarism in Japan's politics.''
Since becoming prime minister last November, Nakasone has devoted much attention to cultivating relations with China.