We aim to elucidate suitable mixed color of light during development of fruit body in Pleurotus ostreatus. The fourmixed color of LED(Light Emitting Diode), blue and white, green and white, blue and green and green and red LED, wereirradiated for formation of fruit-body. First, as effect of mixed color of LED, the properties of fruit body of P. ostreatus in blue andwhite LED irradiation were showed higher commercial yields than those in control(fluorescent lamp). And the ergothioneine wasthe highest at the blue and white LED. Second, we could obtain higher commercial yields than those at the 1 μmol/m2/s of lightintensity by blue and white LED in P. ostreatus.