A method for preparing neoplastically transformed cells from human-derived cells, including the step of introducing human telomerase catalytic subunit (hTERT) gene, SV40 small T antigen (SV40ST) gene, and an oligonucleotide derived from Alu7 sequence into the human-derived cells. A method for introducing a gene for neoplastically transforming human-derived cells, including incorporating human telomerase catalytic subunit (hTERT) gene, SV40 small T antigen (SV40ST) gene, and an oligonucleotide derived from Alu7 sequence into the same or different vectors, and introducing the genes into human-derived cells therewith. The methods of the present invention can be utilized upon induction of neoplastic transformation to various human normal cells in order to elucidate mechanisms for onset of cancer, so that the method can be effectively utilized in the search of a new drug discovery target molecule.