There has been controversial in eastern sector of the Gangdise belt. Through the analysis on geochemistry of rock, this paper found out the Nuocuo Fm. and Laigu Fm. possess transitional characteristics from the alkalis series and own bimodal igneous tectonic features. The average chemical composition of the basalt in the Gangdise belt is closer to continent tholeiite; all the microelements are enriched except Ti，Yb and Y; of them Rb，Th，Ce are more obviously high; rare earth elements showed LREE enrichment,Eu,Ce anomaly not observable.These data showed that the characteristics of Carboniferous tholeiite are similar to continental tholeiite. On the tectonic discrimination diagrams, the tholeiite samples of the basalt from the eastern sector of the Ganddise are focused on the intraplate continental stretching belt or beginning rift. So it is considered that the eastern sector of the Gangdise belt in Carboniferous belongs to an intracontinental rift or a rift on passive continental margin.