Abstract: The genetic structure of Kandelia candel in a mangrove swamp in Taiwan was examined．Using isozymes as genetic markers,it was demonstrated that this species has a little genetic differentiation within population(Fst= O．043)．Low genetic differentiation among subpopulations reflects potential influences of gene flow．It islikely that environmental stress,created by the dry and wetmicrohabitats,is an important force that has potential to influence the growth rate of Kandelia candel．However,it does not have the potential to in-fluence patterns of genetic structure within local population in mangrove swamp.