This study was use of P element of the Drosophila melanogaster to obtain transformed Bombyx mori. To induce transformations by artificial introduction of genetic materials, a simple method of microinjection of DNA into eggs was developed using a microinjector and micromanipulator. The DNA to be injected is comprised of two components. The first consists of a helper plasmid containing a defective P element that although capable of producing the P transposase which can act in trans on another P transposon, is itself immobile. The second component consists of a transposon construct. The vector for this study is pUChsneo. pUChsneo has lacZ which has been used in many different kinds of expression assay. Amount of coinjected DNA is 0.06 ng. The hatchability is about 1 %. The larvae derived from DNA injected eggs and their progenies. To identify transformants, we analyzed by PCR and X-gal staining.