To determine the optimum sowing date and nursery period in Alisma piantago in the southern area of Korea, Alisma plantago local cultivar was grown under three different sowing dates and nursery periods. The plant height, leaf width and leaf length at the area sown on the seedbed in June 30 and conducted the growing seedling in 30 days is 12.1cm, 2.5cm and 3.1cm respectively and it shows tess decrease than that of plant height, leaf width and leaf length with 12.3cm, 2.6cm and 3.2cm respectively which was sown on the seedbed in June 20 and carried out the growing seedling in 30 days, and it also shows less decrease than that of plant height, leaf width and leaf length with 15.2cm, 3.1cm and 5.2cm respectively at the area sown on the seedbed in July 10 and condected the growing seedling in the same date. The stem length, number of stems and diameter of root at the area sown on the seedbed in June 30 and conducted the growing seedling in 30 days is 31cm, 11 and 3.7cm respectively and it shows more increase than that of stem length, number of stem and diameter of and on the other hand shows tess decrease than that of stem length, number of stems and diameter of root with 30cm, 10cm, 35cm respectively which was sown on the seedbed in 30 days, and on the other hand shows less decrease than that of stem length, number of stems and diameter of root with 32cm,13cm,3.9cm respectively at the area sown on the seedbed in July 10 and conducted the growing seedling in the same date, The fresh yield of roots at the area sown on the seedbed in June 30 and conducted the growing seedling in 30 days is 431.4Kg/10a and it shows more increase of 26.9Kg than that of fresh yield of root with 410.59g110a which was sown on the seedbed in lune 20an4 carried out the growing seedling in 30 days, and it also shows more increase of 7Kg than that of fresh yield of root with 430.4Kg/10a at the area sown on the seedbed in July 10 and conducted the growing seedling in the same date. The dry yield of roots at the area on the seedbed in June 30 and conducted the growing seedling in 30 days is 351.9Kg110a which was sown on the seedbed in June 20 and carried out the growing seedling in 30 days, and it also shows more increase of 16.4Kg than that of dry yield of root with 335.4Kg110a at the area sown on the seedbed in July 10 and conducted the growing seedling in the same date. Therefore, the seedling period of proper seedbed for high yield bumper crop of Alisma plantago for exporting to Japan is June 30 and the number of days for seedling is 30 days.