PURPOSE: To obtain the title dope useful as a stock soln. for the molding of high-performance polyimide aramide having excellent heat resistance and physical properties, by blending a copolymer composed of a polyimide structure unit and a para type aramide structure unit with sulfuric acid.

CONSTITUTION: A dope consists of a copolymer (a) having an intrinsic viscosity of not lower than 2.0 and composed of a structure unit [I] of formula I and a para type aramide structure unit [II] of formula II in a copolymerization molar ratio of [I] to [II] of 10/90W80/20 and sulfuric acid (b). In the formulas, Ar1, Ar3 and Ar4 may be the same or different groups and each is a para- orienting bivalent arom. residue; Ars is a tetravalent arom. residue; H atoms on said arom groups may be substituted by the same or different non-reactive functional groups. Heat-resistant molding products having high strength and molecular orientation are formed merely by molding said dope.