Abstract: This study was conducted to investigate the effect of soybean protein peptide on the growth performance of young animals by using weaned piglets as experimental animal. A total of 160 weaned piglets were included in this study and were randomly divided into four groups. Group I fed basal diet adding 3.0% plasma protein powder; Group Ⅱ fed basal diet adding 3.0% ＂Leneng＂, a commercial production of soybean protein peptide, and 3.0% plasma protein powder; Group Ⅲ fed basal diet adding 3.0%＂Leneng＂; Group Ⅳ fed basal diet adding 5.0%＂Leneng＂. The entire test period lasted for 12 d. The results showed that during 1-6 d, 7-12 d or 1-12 d after weaning, the growth performance of the piglets in groups Ⅱ and group m were both significantly increased （P〈0.05）, and the significant increase in feed conversion rate of the piglets was also observed （P〈0.05）. In view of the cost of feeding, 3% soybean protein peptide was commended to use for weaned piglets.