Abstract: A new in-situ remediation technology for groundwater contamination(permeable reactive barrier)is introduced in the paper,including the configurations,medium selection,mechanism,utilization situation and existed problems of reactive barrier. In practice,the permeable reactive barrier configurations can be changed according to the local hydrogeologic conditions and the characteristics of groundwater contamination in order to effectively catch the contaminated plume.Comparing with pump-and-treat system,the permeable reactive barrier is cheap and durable,with a good effect on the treatment of DNAPLs-contaminated plume.