In view of pipelines laid in landslide mass,a security monitoring system is proposed.A method for evaluating maximum strain value based on strains of three points on the pipeline is presented.Temperature compensated FBG strain sensors are used in monitoring the strains of pipeline.The strain data of pipeline measured by sensors after 5.12 Wenchuan Earthquake is analyzed.The analysis results show that the earthquake has remarkable impact on landslide,which is proved by large displacement of shallow sliding plane.Strains of the pipeline increase obviously but the total value is less than pre-warning threshold,therefore,the pipeline is under security condition.