Abstract: Earthworm is a versatile bio-resource and the hydrolysis products of its protein is a useful material. In order to increase the hydrolysis efficiency , acid protease was used to the hydrolysis of earthworm protein pulp and three outer proteases were used to the hydrolysis of earhworm protein trash. The effect of acid protease on the amino acid concentration for earthworm protein pulp was mainly studied in this paper. Based on the relationship of hydrolysis time and amino acid concentration a regress equation model was developed .The result showed that outer protease had significant effect on hydrolysis of protein trash. The hydrolysis rate of 3 treatment that had outer proteases was increased compared with CK, the sequence was: acid protease＞alkaline protease＞neutral protease. The regression approach equations for the hydrolysis time and amino acid concentration was : Y=0.432371*EXP(0.130930*X)for acid protease treatment; Y=0.260455*EXP(0.143428*X)for CK.The significant test for the equations shown that all got a significant level . The amino acid concentration was increased significantly for the acid protease treatment .The increasing rate of hydrolysis was decreased with the increase of hydrolysis time, and had a negative correlation during hydrolysis process.