Method and system of processing cross-domain cookies in order to allow a first website to access a cookie of a second website are provided. In one aspect, a method includes: providing a flash cookie of a first website in a user's local computer; reading an ordinary cookie of a second website that is stored in the user's local computer; and writing the ordinary cookie of the second website into the flash cookie of the first website. Based on this method, it is achievable to access and store cookies across domains in the user's local computer. Accordingly, the method enables e-commerce websites to have a more comprehensive collection of user information to provide more reliable references for the e-commerce websites to analyze user information.