Abstract: Source apportionment technology of river pollution source with water quality model coupling with chemical mass balance ( CMB) model was developed． This model was used to analyze the contribution of the upstream section，direct discharge industry sources，branch sources and unknown sources to the receptor section of the river． The technology could analyze the relative ratio and absolute value of the specific sources' contributions to the receptor，and have the assessment indexes to evaluate the results． The source apportionment model was applied to the main sections of Xiaoqing River in Shandong Province． It was found that the analytical results coincided with the reality and could meet the demands of the assessment indexes． The organic combination of diffusion and receptor model enhanced the conformity degree between source apportionment results and the actual conditions．