Aim To examine the inhibitory effect of re-combinant cardiac troponin fusion protein composed of subunit I and artificial peptide which was called CIS on tumor growth. Methods The CIS ’ s effect on the growth of human umbilical vein endothelial cells ( HU-VEC) was examined using MTT assay in vitro. Chick chorioallantoic membrane model was applied to study the alteration of angiogenesis treated with purified re-combinant CIS protein. The effect of tumor growth trea-ted with CIS was observed using several in vivo mice xenograft models. Results There was a statistically significant reduction in HUVEC cell proliferative rate when the cells were treated with purified CIS fusion protein, which was also shown in a dose-dependent manner. A decreased amount of new blood vessel for-mation ( angiogenesis) on chick embryo chorioallantoic membranes was observed in recombinant CIS protein treated group compared to the untreated control group. A significant inhibition of tumor growth rate was a-chieved in CIS treated mice compared to CIS untreated control mice in 6 different mouse xenograft models. Conclusions The fusion protein CIS shows the inhibi-tory effect on the tumor growth in our in vivo mouse models, and such inhibition could be mediated by the mechanism of CIS’ s effect on the decrease of HUVEC cell proliferation and further the reduction of angiogen-esis in tumor tissues. This work could provide the foundation for the in-depth investigations on the phar-maceutical application of CIS targeting anti-tumor ther-apy.