Abstract: Influencing factors on Ni bioaccumulation by Synechcoccus were studied. The equilibration time of Ni bioaccumulation was about 80 min in aqueous solution. The bioaccumulation quantity reached a maximum when the mass ratio of Ni to Synechcoccus was between 16%-18%, and increased with the increasing ofpH. The optimum pH was 9-10 because high pH would lead to precipitation of Ni(OH)₂. The bioaccumulation quantity was also influenced by temperature and illumination intensity and the optimal condition was 35℃ and 3000 lx. The bioaccumulation of nonliving algae was lager than that of living algae.