In this study, to further understand the mechanism of animal growth and to develop a miniature transgenic animal model, we constructed and tested tetracycline-inducible RNAi system using shRNA targeting the mRNA of mouse insulin-like growth factor (mIGF-1) or mouse growth hormone receptor (mGHR) gene. Quantitative real-time PCR analysis of mouse liver cell (Hepa1c1c7) cells transfected with these vectors showed 85% or 90% of expression inhibition effect of IGF-1 or GHR, respectively. In ELISA analysis, the protein level of IGF-1 in the cells expressing the shRNA targeting IGF-1 mRNA was reduced to 26% of non-transformed control cells. Unexpectedly, in case of using shRNA targeting GHR, the IGF-1 protein level was decreased to 75% of control cells. Further experiments are needed to explain the lower interference effect of GHR shRNA in IGF-1 protein. Accumulated knowledge of this approach could be applicable to a variety of related biological area including gene function study, gene therapy, development of miniature animals, etc.