Abstract: The leaked products pipeline will absolutely have major affects on rivers along the pipeline, dense residential area and the other paralleled pipelines. Taking the products pipeline in Changqing Petrochemical Corporation as an example, quantitative prediction on the influence of leaked pipeline on the surface water is carried out based on the evaluation indexes in the proportion of water surface covered by spilled oil and the oil film thickness. Prediction conclusion shows that when the massive leaks brought in directly the river will seriously pollute the rivers in the case of medium oil film thickness with large-scale oil film. The possible influence of leaked pipeline on its parallel pipeline is analyzed by the event-tree method. Results from the quantitative computation for the event indicate that the event probability of leaked pipeline will be at 1.1×10^-5 on its parallel pipeline, and the fire probability is at 3.8×10^-5. Therefore, the measures against the pipeline leakage risk will instruct the environment risk assessment in this kind of leakage event.