The relationship between Turkmenistan and Iran is worth studied, whose importance lies not only in the their specialities, but also in that the region of the two countries is hot-point and frontier, involing many problems. First of all, the paper studied the relations between Turkmenistan and Iran in Timurid dynasty period, Safavid Dynasty period, the period when Russia conquered Turkmenistan and the soviet union period, sorted out the relations between the two countries before the independence of Turkmenistan. Then, the paper emphased on the analysis of the relations between the two countries after the independence of Turkmenistan, sorted out some concrete problems in the relations of the two countries,such as economic & trade relations, cooperation in the field of energy, nterconnection, cultural relations etc. The paper also analysed how the great powers influenced the relations between Turkmenistan and Iran. In the process of developing relations with Turkmenistan, Iran has many competitors such as Russia, the United States, European Union, Turkey and so on. Finally, the paper had a brief analysis on the relationship between China and the two countries. At present, China maintains a good relationship in the filed of political, economic, secure and other fields with the two countries. Actually, the steady relationship between Turkmenistan and Iran not only conforms to the two countries’ interests, but also conforms to China’s interests.