This study was to find out optimum rice cultivars for organic farming in no-tillage paddy. A field research was conducted the yield, yield components, and qualities of thirty two Korean rice cultivars, and two Japanese rice cultivars. The column length of early rice plant was shorter in medium maturing rice cultivars compared to early, and medium-late maturing rice cultivars. Planthopper population per20-plant was lower in Ilpumbyeo, Dongjinbyeo, Hojinbyeo, Donganbyeo, and Sobeebyeo in that order while was higherin rice cultivars of early maturity. The disease severity of sheath blight was higher in Saechucheongbyeo>Chucheongbyeo>Namwonbyeo>Sangmibyeo in that order, on the other hand, that was lowerinHwaseongbyeo>Junambyeo>Saesangjubyeo=Hitomebore>Ilpumbyeo>Hwayeongbyeo in that order, respectively. The grain yield of Korean rice cultivars was significantly higher in 2.95 Mg $ha^{-1}$ for Hwasinbyeo, 2.91 Mg $ha^{-1}$ for Ilpumbyeo, 2.86 Mg $ha^{-1}$ for Sobeebyeo, 2.73 Mg $ha^{-1}$ for Naepungbyeo, and 2.70 Mg $ha^{-1}$ for Saegyehwabyeo compared with 1.38 Mg $ha^{-1}$ for Hwabongbyeo, 1.62 Mg $ha^{-1}$ for Hwayeongbyeo, and 1.78 Mg $ha^{-1}$ for Haepyeongbyeo of medium maturing rice cultivars, respectively. Toyo taste value of medium maturing rice cultivars tended to higher than that of early, and medium-late maturing rice cultivars. Ripening rate of rice cultivars was significantly positive correlated with Toyo taste value while negative correlated with protein content. According to principal component analysis, these results show that Sangmibyeo, Sangsanbyeo, and Odaebyeo for early maturity, Naepungbyeo, and Sobeebyeo for medium maturity, and Hwasinbyeo, Chucheongbyeo, and Sindongjinbyeo for medium-late maturity were optimum rice cultivars for organic farming in no-tillage paddy.