Objective To establish a PiggyBac transposase-expressing transgenic mouse model for study of the genetic modification mediated by transposon in mice. MethodsPiggyBac transposase gene was driven by CMV promoter and transgenic mice were created by the microinjection. The gene type of transgenic line was identified by PCR and the gene expression level in testis was determined by RT-PCR. The activity of the PiggyBac transposase was detected with the transposition efficiency by Southern blot in the mice crossed with transposon donor transgenic mice. ResultsSeven lines of transposase transgenic mice were obtained by microinjection. One mouse line with relatively higher expression level of transposase in the testis was obtained and the transposase induced the transposition of the transposon donor DNA fragment in the mouse genome. ConclusionA PiggyBac transposase-expressing transgenic mouse model is successfully established. This model will greatly contribute to the research of the genetic modification mediated by transposon in mice. 