In recent years, a large number of study for rear impact has been conducted and as a result of study, researchers proposed the neck injury criteria and test procedures. But many questions, related to injury criteria and dummy biomechanical levels, remain unresolved. In recently reports, rear impact motions of BioRIDIIg is not humanlike but better than other dummy(HybridIII, RID3d). So, in this paper, 4 times sled test would be done to find the substitutable neck injury criteria in BioRIDIIg. To review corelation trend with neck injury critera and head-neck movement, we compared with recently announced neck injury criteria(NIC, Nkm, T1 ect.) and head-neck X-direction movement in BioRIDIIg. Finally, we find the head-neck X-direction movement on head C.G to T1 point may be considerable as the additional neck injury criteria.