Mouse canstatin is a C-terminal globular non-collagenous domain of type Ⅳ collagen α2 chain, which previously showed anti-angiogenic activity. To investigate in vivo angiostatic effects on chick chorioallantoic membrane(CAM) by recombinant mouse canstatin N-fragment(1～95aa), the cDNA for N-fragment of mouse canstatin, obtained from a cloning vector pMD18T-mCan by PCR, was introduced into an expression vector pET30a(+) to construct prokaryotic expression vector pET-mCanN. N-fragment of mouse canstatin efficiently expressed in E.coli BL21(DE3) after IPTG induction was monitored by SDS-PAGE and by Western blotting with an anti-hexahistidine tag antibody. The expressed N-fragment of mouse canstatin, mainly as inclusion bodies, accounted for approximately 18% of the total bacterial proteins as estimated by densitometry. The inclusion bodies were washed, lysed and purified by the nickel affinity chromatography to a purity of 92%. The refolded N-fragment of mouse canstatin was tested on the chicken embryo CAMs, and a large number of newly formed blood vessels were significantly regressed. It is concluded that N-fragment derived from mouse canstatin is an effective inhibitor of angiogenesis of the chicken embryo in a dose-dependent manner through CAM assay and a promising candidate for the treatment of cancer, suggesting that these novel findings may add to the understanding of anti-angiogenesis effects of the N-fragment of mouse canstatin.