There are a number of methods for measuring the fatigue because the measurement of this in the working hours is useful for analyzing the factors of fatigue and for the utilization of the labor management. In this paper, the fatigue of bus drivers who have experience of various
number of years in some bus company is measured by the flicker and these values are analyzed by X(2) test or sign test and its control limit is determined. These are contributed to find a daily variation and to estimate the fatigue capacity, the degree of skill and what factors have influence on points which oversteps the limit line. It was found in this study that the limit line gets lower as the year of experience increases and the flicker values decrease in the forenoon.