Abstract: In order to assure the safety of oil and pipelines, PetroChina Pipeline Company implements the pipeline integrity management to carry out the pipeline risk assessment. Kent's is a semi-quantitative risk assessment method worldwidely used. It's improved according to the inland condition. Some assessment indexes in corrosion, manufacture and construction, earth movement, maloperation and leak impact have been changed. Then the high risk pipeline segments are screened successfully by the improved methods. Finally the high risk pipeline segments are ranked and corresponding mitigation measures suggestion are provided. The measures are divided into management, inspection, hydrology project and others. PetroChina prioritizes the budget of projects by the risk management, so the effectiveness is improved and the pipeline safety is increased.