Abstract: The geochemistry of sandstones in a sedimentary basin tends to be influenced by provenances,and thus may provide important geological information about the sediments.The analysis of the geochemical signatures of major elements from the Cretaceous Taoqihe Formation and Taipinglinchang Formation sandstones in the Sunwu-Jiayin Basin has disclosed that the source area was once in the tectonic setting of the active continental margin,including continental island arc and oceanic island arc during the deposition of the Taoqihe Formation to Taipinglinchang Formation.The types of parent rocks in the source area include granite,intermediate to acidic volcanic rocks and low-grade metamorphic rocks.During the deposition of the Taoqihe Formation to Taipinglinchang Formation,the Xiaoxing'anling Mountains acted as the main provenance except the deposition of the Taipinglinchang Formation,and the Jiamusi block was always a principal source area in the eastern part of the basin.