Abstract: The current ASTM standard for measuring the mode Ⅰ interlaminar fracture toughness of composite requires to measure the crack growth length, which is a very tedious and difficult process for measuring the interlaminar fracture toughness in low temperature environment. To overcome the limitation of measuring the crack growth length, a double compliances method was used to measure the mode Ⅰ interlaminar fracture toughness. The process of this method was nearly the same as that recommended in the ASTM, except avoiding measuring the crack growth length. To verify the accuracy of this method, five double cantilever beam (DCB) specimens made of carbon fiber reinforced epoxy composites were tested at -10℃ environment. The fracture toughness were determined by using the methods recommended by the ASTM standard and the present double compliances method. The result shows that the relative difference of the fracture toughness obtained from the ASTM methods and the double compliances method is within 5%. Therefore, the present paper provides a simple and reliable method for determining the mode Ⅰ interlaminar fracture toughness of composite in the low temperature environment.