Abstract: Previous studies suggest that trust is a key factor in success of construction projects, and how to describe the trust state between the owner and contractor of a construction project is a very important part of project implementation. This paper summarizes the previously reported key events that represent trust in the DBB mode, and recognizes grips that can measure trust state using the data of interviews and a content analysis method, focusing on clarification of the contract parties' behaviors of trust state. Based on this, we develop a dynamic elevation model of owner-contractor trust state for the overall process of a construction project. The results have shown that the trust grips, as a measure of trust state, can help contacting parties understand better the partner's trust level and judge the effectiveness of various measures for improving the trust state, thus promoting the probability of project success.