ObjectiveTo summarize the research progress in the lower limb lengthening by intramedullary nail. MethodsThe domestic and foreign related literature about the lower limb lengthening by intramedullary nail was reviewed, summarized, and analyzed. ResultsThe intramedullary nail lengthening systems can be divided into 3 types:distraction by mechanical strength, by motorized electronic power, or by motorized magnetic force. The new technology has obvious advantages in complication incidence, limb function, bone healing rate, comfortable and cosmetic degree of the patients, and hospitalization days compared with the external fixation, but it also has the disadvantages including lengthening failure of system breakdown, intramedullary infection, injuries of vessel and nerve, limited distraction length, and expensive price of the apparatus. And the method also has several contraindications:narrow medulla, multiple curves of medulla, osteomyelitis, skin infection, and unclosed epiphyseal plate. ConclusionThe lower limb lengthening by intramedullary nail is a major improvement of Ilizarov technology. Although the method has been used in limited cases, the preliminary clinical results are excellent, and it can be regarded as a new trend of the limb lengthening, bone reconstruction, and deformity correction.