Abstract:K+ channel is a kind of important ways for K+ uptake and transport and plays key roles in ion balance in plant cells. In this study a K+ channel gene was isolated from Hevea brasiliensis by RT-PCR and RACE-PCR technuques and charactirized, showing its cDNA has a total length of 1480bp with an open reading frame(ORF) of 1059bp encoding a precursor protein of 353 amino acid residues. Homology and cluster analysis indictaed that this gene belongs to known KCO family in plants, designated HbKCO1. Semi-quantitive RT-PCR demonstrated that HbKCO1 was present in all plant organs, but preferentially in leaves, strong in stem, latex and bark, and very lower in root. The expression of HbKCO1 in leaves could be significantly induced by high K+, salt(NaCl) and high Ca2+stresses but inhibited by low K+ stress and ABA treatment. In addition, the HbKCO1 transcripts in latex were weakly affected by ET and JA treatments.