A colorless and transparent thermosetting polyimidesilicone resin comprising structural units of the following general formula (1) and structural units of the general formula (4), said resin being soluble in an organic solvent ##STR1##

wherein X is a tetravalent organic group having 4 or more carbon atoms, none of the carbon atoms of X being bound to a plurality of carbonyl groups, Y is a diamine residue and Z is a diaminosiloxane residue.