Erkeshan, Wudalianchi and keluo volcanic groups distribute in a single te- ctonic belt. From Neogene to Holocene, they erupted continuously, Volcanic rocks belong to a seriese of ultrabasic--intermidiate, alkaline--peralkaline potassium-rich rocks. In present paper they are named as picrite-leucitite, oli- vine-leucite basalt and leucitebasalt. The rocks in three volcanic groups are very similar in petrology and geochemistry, that shows their close relationship them. But they are different from Cenozoic volcanic rocks of other areas in northeastern China by high abundance of K2O,AIk and Poor CaO, and characteri- zed by much rich incompalible elements and LREE, the primary magma also has relatively high content of mantle compatible elements(such as Cr, Ni). Consequently, they belong to potassinm-rich type which are ready found in the world。 Based on the petrology, geochemistry and calculation, we suggest that the picrite-leucitite and olivine-leucite basalt were solidified by primitive magma which derived from phlogopite-bearing lherzolite mantle by partial melting, the degree of partial melting is respectively 3.5% and 4.3%about. Leucite basalt was solidified by secondary magma, which was produced by fractional crystallization of a small amount(14%)of accumulative rock from primitive magma and assimilation of granite(28%)。