Abstract- Natural fiber is abundantly availing in nature. Nowadays this is used in composite materials. In general ridge gourd fiber is very strength material due to its woven. So this fiber is using in composites. Here potassium hydroxide (KOH) treated ridge gourd fiber is used in composite. One of the traditional methods, hand lay – up method is to use for preparing ridge gourd fiber reinforcing polyester composite. Specimens are to be test as per ASTM standards. Tensile and flexural strength are analyzed and optimize the parameters. Then, the fractured surfaces are analyzed with the help of SEM images.