In order to detect the ability of EBV on transfecting and transforming human nasopharyngeal epithelia(HNE) isolated from human embryo, the HNE was cultured in vitro and then transplanted into nude mice. HNEs were treated by EBV, EBV + TPA and TPA in vitro, respectively. The mice transplanted with HNE tissues were injected subdermally by EBV, EBV + TPA and distilled water several times, respectively. The morphological changes indicated that EBV induced not only enhancement of foci and N/C ratio in cultured HNE which are important characteristics of malignant transformation, but also carcinogenesis of transplanted HNE, all of the carcinoma were EBV positive. TPA seems to increase EBV transfection rate (EBV PCR positive rate) in vitro, especially in the early stage. TPA alone did not exert effect on malignant transformation Cooperating with TPA, EBV induced early invasive carcinoma in vivo.