The strategic subject of membership in WTO is one of the important subjects in world transactions; and countries from all around the world enthusiastically follow this matter. Since WTO covers 148 countries and more than 95% of world trads, not attending in this realm is not possible and meaningful. Therefore, it is necessary to study about different aspects of commodity, service and industrial property trade. By considering the necessity of joint of Iran to WTO, that is one of the main concerns of capitalists and governors, and since the forth development plan is based upon liberating the commerce; and regading the fact that Iran is accepted as an observer member in WTO (Since 26, May 2005), it is vital that before taking any actions, different aspects of each activity be examined thoroughly. Further more, the legal situation of different services should be examined by the experts to comment upon professional aspects. The above mentioned experts, then, according to the position of services trade in Iran and in the world, evaluate the capacity of different services to recognize the internal market and try to expand it into external markets as well.