Abstract: To research the filling process and deformation law of gob-side entry retaining in Chengzhuang Coal Mine 4311 fully-mechanized caving face, we determined the parameters of filling body through theoretical calculation, researched double liquid filling material to realize long distance transporting technology, and observed the deformation in the retained entry. Results show that 2 meters width of filling body and 1.5∶1 of water-cement ratio can satisfy engineering constraint; single liquid of the filling material has stable performance, is beneficial to realize the long-distance transporting technology; it has rapid growth of resistance performance, can reach to designed strength in three days; floor heaving and filling body deformation are major of entry deformation, both of them take more than 60%, the range from 0 m to 8 m behind face is the drastically changing area, and 210 m behind the face, roof and coal's deformation speed is less than 0.5 mm/d , but floor is in long-term creep because of a lack of support.