Phlebotomus major wui, an anthropophilic species, was predominant among sandflies in Karamay, Xinjiang of China. The females of this species collected in the wild and houses were detected to be infected with promastigotes. Three isolates of promastigotes obtained from P. major wui were inoculated intraperitoneally and subcutaneously into normal hamsters or BALB/c mice which developed visceral leishmaniasis later. The mean size of amastigotes in hamster viscera (smear observation) artificially inoculated with the cultured parasite originated from sandfly was significantly smaller than those in control hamster inoculated with the cultured Leishmania turanica from great gerbils in situ. The promastigotes from P. major wui hardly grew in NNN medium. In addition, 32P labeled gene gp63 was used as probe to hybridize DNA prepared from L. infantum, L. turanica and Leishmania from this sandfly showed that marked homogeneity existed between the isolates from P. major wui and L. infantum. At the present time, visceral leishmaniasis did not occur in Karamay but cutaneous leishmaniasis (CL) has been evidenced. Thus, what is the source of natural infection of P. major wui? Whether L. turanica or L. infantum is the pathogen of human CL in this area? These are interesting aspects to deal with in the further study.