The present invention is a solventless one liquid type cyanate ester-epoxy resin composition having high thermal resistance as well as excellent storage stability and curing properties, which contains (A) cyanate ester, (B) epoxy resin, (C) guanidine compounds and (D) at least one kind of phenol compounds selected from a group consisting of phenol compounds represented by the following general formulae. In the general formulae, 1 is an integer selected from 0 to 4, R1 represents an unsubstituted or fluorine-substituted monovalent hydrocarbon group.;General formula:;