The WIP1-2 gene was cloned from rice. It belongs to the Bowman-Birk inhibitor gene family. Northern blot showed that expression of this gene was induced by wounding and jasmonic acid (JA). It indicates that the OsWIP1 gene plays an important role in the rice defense system. The OsWIP1-2 was cloned into pET28a and expressed in E. Coli. Its expressed product was purified in the form of fusion protein and tested for the inhibitory activities against trypsin and chymotrypsin. It was found that the fusion protein could inhibit chymotrypsin, but not trypsin. It was also found that the His tag at its C-terminal affected its inhibitory activity significantly. The fusion protein with a natural C-terminal had the inhibitory activity, while no inhibitory activity was detected in the fusion protein with a (His)6-tag at its C-terminal. This implies that extra amino acid residues at the C-terminal of OsWIP1-2 may interfere with its correct folding. The inhibitory assay indicated that the members of rice Bowman-Birk inhibitor gene family probably differentiated both in their structure and function.