PURPOSE: To obtain a thermosetting resin composition capable of shortening molding time and improving productivity and simultaneously free from causing deterioration of strength even if the resultant molding is used in a place using water by using a mixture of a high alkali glass fiber and a low alkali glass fiber as a reinforcing material.

CONSTITUTION: This thermosetting resin composition comprises 100 pts.wt. thermosetting resin and 10-60 pts.wt. glass fiber. The glass fiber consists of a mixture of a high alkali glass fiber and a low alkali glass fiber and a monovalent alkali metal oxide content contained in the glass fiber is 0.4-5 pts.wt.