Abstract: K+ channel proteins play key roles in ion balance in plant cells. With the help of eukaryotic or prokaryotic expression system, efficient expression of K+ channel protein is a prerequisite for further study of its biochemical characteristics and physiological functions. Here, a K+ channel gene，HbKCO1 was isolated from Hevea brasiliensis，and expression of recombinant HbKCO1 was investigated. ORF fragment of HbKCO1 cDNA was inserted into the vector pET-28a(+), resulting in pET-28a(+)-HbKCO1, and then pET-28a(+)-HbKCO1 was transformed in Escherichia coli RosettaTM(DE3) pLysS and BL21(DE3), respectively. In the optimum condition, recombinant HbKCO1 could be efficiently expressed in the E.coli RosettaTM(DE3) pLysS transformats after 3h induction of 1mM IPTG, but weakly expressed in the E.coli BL21(DE3) transformats. Prokaryotic expression of recombinant HbKCO1 was strain-dependent.