REE, trace element and Sr, Nd and Pb isotopic data of the Hekanzi alkaline complex are presented in this paper, together with a discussion on its relationship with the regional tectonic regime and its geological implications. Rocks of this complex have high REE contents. In the chondrite-normalized REE diagram, these rocks show LREE enrichment and have weak or very indistinct negative Eu anomalies. The PM-normalized trace element diagram exhibits LREE and LILE (Rb, Ba, Th and Sr) enrichment with negative Nb, Ta, K, P, Ti and Y anomalies. Transitional element contents of the complex are very low compared with data of the primitive mantle. REE and trace element characteristics of the Hekanzi alkaline complex are very similar to those of the Fengcheng alkaline complex in eastern Liaoning Province. A five point whole rock_mineral Rb-Sr isochron for themain intrusive stage of the complex yields an age of 221.4±8.5(2σ) Ma, implying that the Hekanzi alkaline complex results from activity of Indosinian alkaline magma. All εSr(t) values of the Hekanzi alkaline complex are positive with an average of 7.23, and the initial 87Sr/86Sr value obtained from the Rb-Sr whole rock-mineral isochron is 0.704 77±0.000 15. However, all the εNd(t) values are negative. Trace element compositions and Nd, Sr, Pb isotopic geochemical characteristics of the Hekanzi alkaline complex show that its source has features similar to those of the EMⅠ end member These features suggests that the upper mantle of the eastern North edge of North China platform was fertile in Triassic period and, what is more, the upper mantle under the eastern part was more fertile than that under the western part of Liaoning Province. Variation diagrams of major and trace elements imply that the Hekanzi alkaline complex was formed in an intra-plate environment, and its major magmatic process is dominated by batch melting.