Two strains which have good traits in quality and speedy growing were selected based on previous report(Ryu, 2007) to breed a new strain carrying the traits in it. KNR2322 carrying high quality and KNR2503 carrying a speedy growing trait were cultivated to harvest monokaryons. The monokaryotic mycelia were characterized in growth rate, color, and stability. Selfing of monokaryons from KNR2322 and crossing between KNR2322- and KNR2503-derived monokaryons were performed. Two parental lines, KNR2322-4×37-6×12(B) showing thremmatological values in weight and quality, 68.5g and 6.5 and KNR2322-30×KNR2503-60(A) was harvested in 13.5days after scraping old medium were selected. Crossing between A and B resulted in two high quality and speedy growing strain, A8B8and A8B10. Their days for harvest after scraping, weight, and quality were 14.0 days, 88.8g and 92.7g, 7.0 and 7.1. Originality tests were conducted with genomic DNAs of A8B8 and Keuneutari 3ho(commercial strain) by DNA fingerprinting a confrontation culture. The results showed polymorphism and a inhibition line between them. It suggested that the new strain have originality from the commercial strain. A8B8 have been registered in Korea Seed and Variety Service with as “Saesongi 1ho”.