Abstract: The existing forms of chloride salt in Tahe crude oil and their sources were analyzed and an assistant agent H for organic chloride removal was developed and tested. It is found that there are two forms of chloride salts in Tahe crude oil: inorganic and organic chloride and that the content of organic chloride is above 50％. The organic chloride cannot be completely removed by traditional method and mainly goes into residual oil fraction during distillation. The test results show that the agent H with demulsifier together can decrease the chloride content in treated oil to less than 10 ?g/g and salt content to less than 3 mg NaCl/L. Meanwhile it has little disadvantageous effect on demulsification.