A newly isolated Bacillus cereus strain HQ-1 was found to possess high capability to absorb silver ions. The study showed that the biosorption process could be described well by pseudo-second-order kinetic model and Freundlich isotherm model. Higher cell concentration was favorable to the biosorption. Temperature's effect on the biosorption was not obvious. The oxygenous and nitrogenous functional groups on the cell wall played a very important role in the process of biosorption. Microdeposits were formed by interaction between silver ions and biopolymers from the cell wall (such as polysaccharides, proteins and some hydrolysis).