Abstract: This paper researched in the diversified results of several acidizing treatments for the purpose of well stimulation and pressure decreasing which were conducted in No.7 Oil Production Plant of Daqing Oilfield Company Limited. Firstly the main factors that caused formation plug were analyzed, and plugging matter from four districts were analyzed respectively. Then geologic features were studied. Based on above matters, we developed acidizing recipe focused on different districts. Now it has been applied to 20 water injection wells, and water injection pressure decreased by 2.0 MPa and 0.7 MPa, injection rate increased by 24.0 m³ and 17.7m³ in the initial and late stage respectively. The rate of success is increased by 10%, validity period prolonged by 73 days, single well injection increased by 4.7 m³/d compared to the former acidizing results. Field tests indicated that treating results were improved tremendously.