Lithology of the Majiajie Group，located in eastern Heilongjiang Province, is dominated by low metamorphic argillaceous rocks. Major and trace elements analysis shows that content of SiO2 is 61.5%~77.68%，Al2O3 is 9.74%~21.08%，K2O is 2.73%~6.34%，Na2O is 0.1%~2.66%，(La/Yb）N is 6.55~10.79，Eu/Eu* is 0.45~0.64，and （Gd/Yb）N is 1.28~1.94. All these features indicate that the source rock of the Majiajie Group is felsic rocks originating from the postArchean upper continental crust which belonges to continental island arc. The cathodoluminescence images of zircons selected from basal granitic gneiss show that they all have a clear oscillatory zonation and good crystal shape, which indicate they are typical of magmatic origin. The zircon LA ICPMS UPb dating of spots indicates that their 206Pb/238U ages range from 499 to 508Ma and that the weighted mean age of 11 analyzed spots is 504 2Ma. This result indicates the source rock of basal granitic gneiss is middle Cambrian in age while its metamorphic age should be much later than middle Cambrian. Therefore, the Majiajie Group's sedimentation started after Cambrian. The geochemistry of Majiajie Group and geochrolonogy of basal granitic gneiss suggest that the source rock region was probably a stable continental block which was amalgamated by the Jiamusi Blcok and adjacent blocks during PanAfrican period.