Soybean self-sufficiency in Korea was 22.5% in year 2011, and as free trade agreement between Korea and US comes into effect, the amount of soybean importation increases. In 2012, paddy field soybean cultivation was over 0.1 million ha and it is expected to increase continuously due to rise in market price of soybean. Moreover, double cropping system including paddy field soybean is widely adopted nationwide, but studies on appropriate cultivar for this environment are insufficient. In this research, the effect of planting date and different cultivars on soybean growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with 15 cultivars. According to ANOVA test, soybean yield was significantly different depending on sowing date and cultivars and interaction between sowing date and cultivars was also detected, meaning each of cultivars resulted different yield depending on sowing date. When planted on July 20, stem length, nod number, branch number and grain weight was decreased because of short growing period, resulting in yield decrease. Percentage of yield obtained from July 20 in contrast to that of June 20 showed that Pungwon, Nampung and Daepung recorded the least yield decrease and the highest yield when planted late. Evaluation of late-sowing-adaptable soybean cultivar in paddy field is now being carried on following last year.