In this thesis, the meaning of website quality and the parameters that affect on it were surveyed entirely. The most important factors of website quality that may cause a website to be more useful and also to become more successful were found. In this research first of all, in literature review that is in chapter two, the meaning of market, electronic market, Business to customer (B2C) form of the electronic commerce and also more recently specific website issues are going to be mentioned. At the half-end of chapter two, website quality as one of the most important and effective factors of website specific issued was illustrated completely. In the chapter three the research methodology of this thesis was designed that is how to rank all the affected parameters on website quality by help of technique for order preference by similarity to ideal solution (TOPSIS) and then to compare all the result of it by fuzzy TOPSIS with using fuzzy trapezoid numbers. Then it will shows how to interview with expert just in order to make the pairwise matrix so that it will give all the ranking factors weight through using analytical hieratical process (AHP), using fuzzy trapezoid numbers too. Finally, eight of the most important factors of website quality was ranked through the fuzzy TOPSIS and then were weighted through the AHP fuzzy. In chapter four, data gathering and analyzing the data that included the description of TOPSIS, fuzzy TOPSIS, and fuzzy AHP methods with trapezoid numbers and also the calculation tables was demonstrated completely. At the end in the chapter five, there is a conclusion part of thesis and the references in follows.