Abstract: The mode Ⅱ fracture failure is one of the basic modes in the soil mass,and the test method of mode Ⅱ fracture toughness is the weak point for study of the fracture characters of soil mass at present.In this paper,the basic theory and methods of each test are introduced at first,and then based on the characteristics of the soil mass,the feasibility and reliability of each method for testing the mode Ⅱ fracture toughness are analyzed.We focus especially on the anti-symmetric four-point bend(ASFPB) test method which has been often used for testing the mode Ⅱ fracture toughness of the soil mass,and based on it we propose a new method.In the new method,the specimen is a single-edge cracked one and its structure is simple;in order to make sure the reliability of the test results,the shear load is directly applied to the soil specimen and the specimen turns fractured in a pure mode Ⅱ condition.