Abstract: A Monte Carlo code applied to radiation protection and medical radiology is presented. It simulates the irradiation caused by photons and can give the effective dose equivalent (H_e)and absorbed dose equivalents of 20 organs (tissues) in a reference man. A special method which divides all photon histories into several kinds and traces each kind separately was adopted to improve the precision of the calculated results.The code can be also used to other calculations of doses in systems with complex geometry.

Key words: Monte Carlo method, reference man, effective dose equivalent