Abstract：The two major issues in front of the worldwide mining industry are work safety and protection of ground environment when carrying on underground mining activities. Cut-and-fill mining method is increasingly applied in China owing to its advantages of controlling ground pressure and protecting the ground environment effectively. However，few works and reports are known on the topics of large-scale rock mass movement and ground fissures resulting from the mining with backfill. An introduction to the phenomena of the ground surface deformation and ground fissures due to underground mining is given in Jinchuan Nickel Mine which is the largest underground mine with cut-and-fill mining in China. In 1999，many ground fissures and breakage on the ground surface appeared in Jinchuan No.2 Mine. Following an introduction to the distribution of the ground fissures and the correlation of the fissures with the location of underground ore body is presented. The emphases are put on the field investigation and monitoring for the fissures. A new type of three-dimensional fissure instrument IGG–1 is invented to measure the change of the fissures with the mining. The results of the measurement show that the three-dimensional displacement characteristics are distinct for the ground fissures. The mechanism and the influential factors are revealed from the field exploration and monitoring. It is shown that the stress redistribution in surrounding rocks resulting from the mining，low stiffness of the filling body，the existence of the void space underground and the influence of on-going mining activities are the main reasons for the occurrence of ground fissures. It is thus concluded that in mine design with cut-and-fill mining，the ground surface deformation and fracture must be taken into consideration.
