In countervailing-duty(CVD)investigation，just like anti-dumping investigation，there exists an issue of price comparison and benchmark selection. The paper analyzes of the regulations and practices of， theU.S.and Canada，twoWTOmemberswhichinitiatedCVDinvestigations against China，andfinds that the two countries have different legal principles behind the CVD benchmark determination. Besides， in the cases against China，we find that they offer different treatment towards China concerning the external benchmark applicability and follow different procedures regarding benchmark selection and price comparison . But there is one thing in common : whether the external benchmark or the internal benchmark is applied to China rests on whether China ' s market economy status or market-oriented industry is determined in the relevant antidumping investigation . This is probably an important base on which other WTO members will decide the external benchmark applicability when they initiate CVD investigation against China in the future.