The experiment was carried out to investigate the effects of phosphate fertilizer level on growth, crude protein content and nitrogen fixation ability of alfalfa(Medicugo sariva L.) at sowing year. The experimental field was conducted using a randomized block design with three replications according to the phosphate application level (200 and 400kfia) in farm of Kongju National University. Research samples were collected at intervals of 7 days from October 7 to December 9 and nitrogen fixation activity of nodule was measured by using the acetylene reduction method (Hardy et al. 1968). The results obtained are summarized as follows : 1. Number of branches, root length and dry matter weight at phosphate fertilizer level of 400kg in sowing year were more increase than those of 200kfia. The number of nodules was not significantly difference between phosphate fertilizer level, because of low temperature to be enough to nodulation of alfalfa. 2. The crude protein content of leaf, stem and root were not significantly affected by the phosphate fertilizer level. but that of leaf was increased at 400kgha on 72 days after sowing. The crude protein content of each part according to growing stages was increased at 44 days and 72 days after sowing. 3. The dry weight of root was not significantly difference between phosphate fertilizer level from 30 days to 51 days after sowing, but that was increased at phosphate fertilizer level of 400kgha from 51 days afier sowing. 4. The amount of ethylene in the samples taken 2 hours and calculated amount of nitrogen fixation were increased at phosphate fertilizer level of 400kfia from 30 days to 65 days after sowing. but there was vice versa from 58 days after sowing.