A subject of the invention is to provide a resin composition which includes a polyimide. The polyimide is soluble in a solvent and a film obtained under a high temperature has high viscoelasticity and softness. In order to solve the subject, a polyimide resin composition of the invention includes the polyimide containing a polycondensation unit of a tetracarboxylic dianhydride and a diamine, wherein the tetracarboxylic dianhydride includes an dianhydride (α1) represented by a general formula (1), or the diamine includes an aromatic diamine (β1) represented by a general formula (2), and the diamine includes an aliphatic diamine (β2) represented by a general formula (3) or a general formula (4). In contrast with a total amount of the tetracarboxylic dianhydride and the diamine, a total content of the dianhydride (α1) and the aromatic diamine (β1) ranges from 5 mol% to 49 mol%, and an amine chemical equivalent ranges from 4000 to 20000. (In the formula (3), R1 is an aliphatic chain) H2N-R2-NH2………(4) (In the formula (4), R2 is an aliphatic chain)本發明的課題在於提供一種樹脂組成物，其包含可溶於溶劑、且所獲得的膜於高溫下具有高黏彈性與柔軟性的聚醯亞胺。為了解決課題，本發明的聚醯亞胺樹脂組成物包括聚醯亞胺，聚醯亞胺包含四羧酸二酐與二胺的聚縮合單元，四羧酸二酐包含由通式(1)所表示的酸二酐(α1)、或者二胺包含由通式(2)所表示芳香族二胺(β1)，且二胺包含由通式(3)或通式(4)所表示的脂肪族二胺(β2)，相對於四羧酸二酐與二胺的合計，酸二酐(α1)與芳香族二胺(β1)的合計含量為5莫耳%~49莫耳%，且胺當量為4000~20000。(式(3)中，R1為脂肪族鏈)H2N-R2-NH2………(4)(式(4)中，R2為脂肪族鏈)
