TODAY ONE OF THE MOST COMMON METHODS IN STABILITY ANALYSIS FOR QUANTITATIVE ASSESSMENT OF HUMAN BODY POSTURAL FLUCTUATIONS IS MEASURING DISPLACEMENT OF CENTER OF MASS AND CENTER OF PRESSURE. IN THIS STUDY, WE USED EIGHT AMATEUR ATHLETES AND SIX PROFESSIONAL ATHLETES IN WUSHU. THE PATTERN OF THE CENTER OF MASS AND CENTER OF PRESSURE DISPLACEMENTS DURING PERFORMING THE MOTION WAS  RECORDED. USING LYAPUNOV STABILITY THEORY, STABILITY AND PREPARATION OF ATHLETES WERE PREDICTED AND THE BEST MODEL IN THE BALANCE MOTION WAS SHOWN TO THE COACHES. RESULTS FROM THIS STUDY SHOWED THAT POSITIVE LYAPUNOV EXPONENT IS DUE TO IMPROPER MOTION PATTERN AND LACK OF ENOUGH PREPARATION OF ATHLETES IN THE BALANCE MOTION