Abstract: The oil production of wells in Dafeng Oilfield decreased rapidly after first fracturing, and refracturing were needed. A set of refracturing technology systems had been proposed, including comprehensive evaluation before and after refracturing, refracture optimization, strict quality control and so on. The key was countering the problem that fracture height spread excessively and matching the fractures and well pattern through indoor research and oilfield experiment. Two experiment wells refractured, the oil production of two wells increased from 0.02 t/d and 1.0 t/d to 5.0 t/d and 4.5 t/d respectively, and the cumulative oil production was 134.0 t and 129.5 t in 90 days, the average oil stimulation was 1.46 t/d. the water cut ratio of a well decrease from 98.0% to 80.0%, and the other one keep constant. Oil stabilizing and water control had been realized, the refracturing level was improved, and considerable economic benefits were achieved.