These studies were carried out to find out the proper plant spacing and the optimum amount of nitrogen for maximum yield, on the occasion of early planting with creen vegetable (soybean for cook with rice) at the low temperature in early spring. The plant spacing were applied in 5 levels (50cm$ imes$5cm, 50cm$ imes$10cm, 40cm$ imes$10cm, 30cm$ imes$10cm and 30cm$ imes$20cm) and the amount of nitrogen were applied in 4 levels (non, standard, twice and triple-amount), The triple super phosphate and potassium chloride were applied only in standard amount. The promotion of flowering was practised by the short-day treatment for 10 days (11 hr. a day). The variety examined was the early maturing one, HOKKAI # 1. and the results are as follow. 1. The plant spacing for maximum yield by the promotion of branch, pod and garin per a plant recognized the fact that there were 2 levels (50cm$ imes$10cm and 30cm$ imes$20cm planting method) and the maximum yield by the promotion of pod and grain per area showed the fact that there were 2 levels (50cm$ imes$5cm and 30cm$ imes$10cm planting method) in narrow planting method. 2. The optimum amount of nitrogen applied for maximum yield of pod and grain per area recognized w hat was sufficient as standard amount.