Abstract: Buried pipelines are widely used in the transportation of liquid and gas media such as crude oil and natural gas. Because of severe working environment, leakage and explosion are likely to happen. The indirect testing technique plays one of the most important roles for insuring operation safety for buried pipelines. The indirect testing techniques used by in-service testing of buried pipelines are reviewed, including in testing the soil corrosion, coating and the cathode protect(CP) of pipelines. The advantage, disadvantage and purpose using these indirect testing methods are indicated.