The unclassified tailings from the mill are filled into underground by use of the techniques of cemented filling with unclassified tailings. This doing can reduce or even eliminate the occupied land which tailings were stored on the surface, avoid the environ-mental pollution caused by tailings storage, save the constructing and maintaining costs of tailing pond, and meet the requirements for mining with filling. In the past more than 10 years, There is a greater progress in the study on the techniques of cemented filling with unclassified tailings. The authors use the specific examples to make a more detail introduc-tion to the present situation of the study on the application of cemented filling with unclas-sified tailings, and an approach to its future trend.