The influence of seed maturity, stratification, and seed washing method on seed germination were investigated for establishment of seed propagation system in dropwort (Oenanthe stolonifera DC). Seed germination rate was increased as period of the seed ripening increased, especially the seed over 40 days after flowering showed the highest germination rate. The optimum period of cold stratification treatment to promote seed germination was about 8 weeks. The seed treated by a cold wet stratification with sand exhibited higher germination rate compared to the seed treated by a cold wet stratification without sand. The stratified seeds that were stored in the ground having fluctuating temperature were improved up to 19%, while stratification stored under constant temperature(4℃) did not improve germination rate. In addition, 8 weeks of stratification period under fluctuating temperature in the ground was most effective. Sodium hypochlorite, vital oxide, and distilled water were used as chemicals to remove the germination inhibitor of seed coat. Water washing of seed coat after soaking in 0.5% sodium hypochlorite and 0.0005% vital oxide for three minutes and 60 minutes respectively could effectively remove the germination inhibitors in the seed coat.