<正>Chlorine-implantation of silicon has a number of applications, for example, possible effects due to introduction of chlorine by plasma etching of silicon wafer as a procedure of device techniques, or chlorine implantation as a proposed efficient n-type doping method. However, the microstructural evolution in chlorine-ion implanted silicon has not been systematically studied.Un the present work we carried out some study with emphasis on the dose dependence of microstructures. P-type silicon specimens were implanted