Heilongjiang mélange distributed in Yilan area of Heilongjiang Province is regarded as the tectonic mélange with features of suture zone. Some metam orphic basic lavas consisting of quite a few metamorphic minerals without directional characteristics are named massive blue schist. The existence of large quan tities of glaucophane, a characteristic metamorphic mineral, indicates that these basic lavas have undergone high –P low –T metamorphism. Geochemical analyses of major elements show that all the samples have the following characterist ics: SiO2＜53%, TiO2＞2%，and Na2O+K2O=2.77%～6.41%. Geochemical analyses of trace elements reveal that the fractionation between LREE and HREE is quite obvious and the distribution pattern of REE is right oblique, with no negative Eu anoma ly in the chondrite-normalized diagram. Na2O+K2O-SiO2 variation diagram indicates that metamorphic basic lavas have characteristics of alkali basalt, and the Nb×2-Zr/4-Y, Ti/100-Zr-Sr/2, Ba-Th-Nb-La diagrams all suggest that these metamorphic basic lavas have characteristics of alkali ocean island basalt (OIB). The above understanding provides important evidence for the research on subduction of the palaeo-ocean crust between Jiamusi continental block and Songnen continental block.