MONDALE

With his tough talk on corporate taxes and his support for a go-slow approach to business deregulation, Democrat Walter F. Mondale is seldom mistaken as the business community's candidate for president.

But on certain key issues, including the use of credit subsidies and import protection, Mr. Mondale would offer more aid to business than President Reagan.

In recent years Mondale has had a chance to see how business works from the inside. After the Carter-Mondale team was defeated in 1980, Mondale was elected to the board of directors of Control Data Corporation, the Minneapolis-based computer manufacturer, and Columbia Pictures, which then was controlled by Allen & Co.

That has not kept the former vice-president from sprinkling his campaign speeches with promises to fight for the ''heart and soul'' of America rather than the ''bonuses of the Fortune 500.''

And in his acceptance speech at the Democratic convention, Mondale said, ''To the corporations and the freeloaders who play the loopholes and pay no tax, my message is: Your free ride is up.''

Mondale's plan for cutting the federal deficit would impose a 15 percent minimum tax on corporate income. When coupled with limits on what the Mondale camp describes as ''tax shelters, loopholes, and accounting abuses,'' the provisions would raise an estimated $25 billion in revenue by 1989.

In terms of deregulation, Mondale promises to move more slowly than the incumbent. However, he notes that the Carter-Mondale administration deregulated the trucking and airline industries.

Mondale supports the deregulation of natural gas prices but opposes the President's attempts to accelerate the process. Mondale also opposes decontrolling the price of so-called old gas - from wells in service before April 1977. He argues that it would ''harm the economic recovery and hurt consumers.''

While taking a tough tack on some business issues, Mondale would be more aggressive in providing certain types of aid than the Reagan administration. To boost exports, for example, he calls for more extensive use of credits, subsidies, and technical assistance from the Export-Import Bank and the Commodity Credit Corporation.

He would match foreign trade subsidies ''dollar for dollar'' until other nations ''agree to sit down with us and negotiate a balanced and fair rate of support'' for exports.

Mondale also would provide specific import protection for certain key industries like automobiles and steel. Unlike the Reagan administration, he supports domestic-content legislation, which would require foreign-made cars sold in the US to contain a large share of US-produced parts.

To help the steel industry, Mondale favors restricting imported steel products to 17 percent of the domestic steel market for five years. But, he says , the limits would be ''in exchange for commitments by the (steel) companies to reinvestment and modernization, and by business and labor to price restraint.''

The US needs a new industrial policy, Mondale argues. The policy would be fashioned by an economic cooperation council made up of representatives of government, business, and labor. Their tools would include grants, loans, tax breaks, and import protection.