INTRODUCTION: IN THE MAIN PART OF THE 20TH CENTURY CONSTRUCTING HARD STRUCTURES HAVE USUALLY BEEN THE PREFERRED OPTION FOR CONTROLLING A RANGE OF BEACH PROBLEMS, INCLUDING BEACH EROSION AND LONGSHORE DRIFT. THE REPLACEMENT OF SANDY BEACHES OF THE SOUTHERN COASTS OF THE CASPIAN SEA IN THE AMIRABAD COMPLEX FREE ZONE WITH PORT GROYNES AND SEAWALLS AND OTHER COASTAL PERSEVERATION STRUCTURES (JETTIES, BREAK WATER) HAVE CAUSED GREAT DAMAGES CONCERNING ENVIRONMENTAL PARAMETERS AND BEACH EROSION HAZARD DEVELOPMENT IN THE AREA. IN FACT IN THIS RESEARCH WE ARE MEASURING THE IMPACTS OF COASTAL MODIFICATION ON THE BEACH EROSION HAZARD AND BEACH RETREATMENT CONDITION.