Abstract: The present study was carried out to uncover the relationship between root nodule and plant growth development of soybean. Root length, root biomass, shoot length, shoot biomass, root nodule number and root nodule weight of soybean was examined regularly during the whole growth period by pot experiment in green house. The result was showed that shoot height, shoot dry weight, root dry weight and fresh nodule weight were changed from slowly rising to fast rising to fast declining to slowly declining. The maximum value of shoot height, shoot dry weight, root dry weight and fresh nodule weight were appeared at 66 days, 72 days, 66 days and 60 days after emergence respectively. However, root length increased fast after emergence. Root length kept in a stable period during 48 days to 78 days after emergence. Number of root nodule increased sharply during 20 days to 30 days after emergence. Then it was increased slowly. After reaching its maximum 54 days after emergence, number of root nodule began to decrease. The above results indicated that number of root nodule of soybean was increased rapidly during early-growth period and kept at the maximum up and down for a long period. The growth rhythm of fresh nodule weight was the same as that of shoot and root dry weight.