Abstract: It has been almost five years since the first report of live pig produced by somatic cell nuclear transfer (SCNT) technology. Though it is more difficult, lower efficiency, compared to embryonic cell nuclear (ECNT) technology, the cloning pigs with SCNT technology has been further studied. Some progress has taken in the fields of mechanism and approaches. In this paper, we mainly focus on the key technology and its difficulties of SCNT in cloning pigs, including its applications and approach of increasing the efficiency of SCNT.