Late Cenozoic basaltic rocks in Wudalianchi and Chinpohu areas of Heilongjiang Province, northeast China include alkali–olivine basalt, leucite basalt and basanite. The alkali basalts from Wudalianchi are higher in Si, Mg, K, P, Ni, Zr, Rb, Ba and LREE but lower in Ti, Al, Fe, Ca, Na, Ta, Th, Sr and Y when compared with alkali basalts from East African province. The most striking chemical features in Wudalianchi alkali basalts are the high potassium (averaging 5.10%) and Ba (averaging around 1800 ppm) contents. The alkali olivine basalt and basanite from Jingpohu are higher in Fe, Mg, Ca and Ta but lower in K, P, Ni, Zr, Hf, Nb, Rb, Sr, Ba and LREE than alkali olivine basalt and basanite from Wudalianchi. Regular variations have been found in major and trace elements vs 100(MgO/MgO+FeO t) plots for alkali basalts from Wudalianchi and Jingpohu suggesting that fractional crystallization has occurred after the formation of the initial liquid. We suggest that the various alkali basalts from Wudalianchi and Jingpohu areas were derived from a mantle source which had been metasomatized and enriched in incompatible elements with a general characteristic similar to EM I defined by Weaver (l991, Earth Planet. Sci. Lett., 104, 381–397). The La/Ce ratios of Wudalianchi basanites tend to increase with younger ages which may be interpreted as due to the decrease of the degree of partial melting of the metasomatized mantle in the younger lavas.