The Reagan administration yesterday disclosed details of its proposed corporate minimum tax, listing the preferences that would become liabilities for firms paying little or no federal income tax.

In prepared testimony to the House Ways and Means Committee, Treasury Secretary Donald T. Regan said the proposed levy is designed to "tax 'corporate profits', that is, regular taxable income plus certain deductions, and would apply only to those corporations that pay very low rates of tax."

It would replace the existing "add-on" minimum corporate tax, which is not targeted exclusively at low taxpaying corporations, and would be applied only as an "alternative" when corporate tax liabilities dropped below a set floor.

In calculating whether the alternative tax is owed, a corporation would determine its taxable income, then add back deductions taken from 13 different preferences or loopholes, exclude $50,000 and take 15 percent of the remaining amount. If that figure exceeds tax liability as calculated using regular methods, then the corporation must pay the alternative tax. If it does not, then the corporation owes only the regular tax.

The key to the formulation of the minimum tax is the selection of the tax preferences, which if used to reduce liabilities significantly become, in effect, penalties. At the hearing yesterday, opposition to some of the administration's choices began to emerge.

The administration included four preferences from the existing law and nine new ones. The four are percentage depletion, accelerated depreciation on real property in excess of 15-year "straight line" depreciation, amortization of pollution control and child-care facilities in excess of normal depreciation, and reserves for losses on bad debts of financial institutions in excess of levels based on past expereience.

The nine new preferences would be: intangible drilling costs in excess of the amount allowed had amortization been 10 years; mining costs in excess of 10-year amortization; "leased" tax breaks in excess of the amount of the break had there been straight line depreciation over the life of the lease; deductions on interest on debt to finance tax-exempt securities; deferred income from domestic international sales corporations; shipping income in capital construction or construction reserve funds; amortization of motor carrier operating rights, a break created in the 1981 tax bill; original issue discount interest deductions in excess of amounts that would be deductible under a constant interest rate; and deductions of indirect costs on long term contracts initiated before Sept. 25, 1981.