Abstract: The knowledge intensive feature of software enterprises and different people's characters in the development team decide that, trust plays an important role in the team's knowledge management. Through elaborating software development team's feature and trust's definition, this paper identifies the definition of trust in software development team, illustrates the trust's influence mechanism to the software development team's knowledge management. On the base of former research on knowledge management and trust mechanism, it combines the form of trust and radius of trust, and gives a dynamic development model of trust in the software development team.