This study was carried out to determine the proper nitrogen and phosphorus application levels for Japanese millet(Echinochloa crusgalli var. fruntentacea). This crop was grown in May-August, 1980. The experiment was based on a factorial design with the levels of nitrogen (0, 10㎏/l0a) and five levels of phosphorus (0, 5, 10, 15, 20㎏/l0a). Potassium was applied at the same rate throughout(10㎏/l0a) except on the control plot, which received none. The results obtained are as follows 1. In the non-nitrogen treatment, the growth of Japanese millet was improved by phosphorus in the early stage of growth but the effect became irregular later on. 2. The nitrogen treatment got a good growth in proportion to apply more phophorus in whole stage of growth. 3. The linear regression equation between the plant length and the dry matter yield was Y＾=6.59X+405.02(r=0.95) and was highly significant. 4. The total dry matter yield from the single nitrogen treatment(P$lt;0.01) increased markedly with increasing phosphorus level(P$lt;0.05). The non-nitrogen treatment showed an irregular trend with increasing phosphorus. 5. The l0a with 10㎏ nitrogen and 20㎏ phosphorus gave an income of ￦32,235, the highest gross income among the ten fertilizer treatments.