An analytical methodology of fluctuation in the body balance is proposed for evaluation of safety of walkway environment which generates a harmful walking mode. First, experiment on transferring platform mock-up is attempted and the motion of human body under some harmful walking environmental condition is measured by motion capture technology on video imaging analysis. Then, the fluctuations in the body balance during walking are extracted as recurrence plot which is originating from applied chaos theory. Furthermore, differences in the fluctuations between on a flat floor as safety environment and on other harmful environments are quantified and extracted as degrees of discordance. By this proposed fluctuation analysis, a safety assessment of various environments is attempted.