Abstract: Based on insite anchor shear tests under natural condition and saturated condition on Changjiang Bridge at Yuzui, Chongqing and the engineering geology, a comprehensive analysis on the influencing factors of shear strength on the contact surface between higher strength concrete and hard bedrock is presented in this paper. The analysis demonstrated that firstly as for the higher strength concrete and hard bedrock, the increasing of concrete strength has slight impact on friction-coefficient (f) on the contact surface, while remarkably helps the increase of cohesive strength (c) .In this sense, it is critical to ensure the quality of pouring on the contact surface between concrete and bedrock. Secondly, the shear strength is reduced slightly by the impact of water, which is quite limited；and the decrease of shear strength under high water head and long time immersing needs to be studied indepth. Moreover, the shear destruction on the contact surface between high strength concrete and bedrock has the characteristics of typical brittle-racture.

Key words: Yuzui Changjiang bridge ,  , contact surface between concrete and bedrock ,  , shear strength ,  , influencing factor