The purpose of this study was to develop a simple and safe submaximal graded cycling test(submaximal GCT)for evaluation of cardiorespiratory fitness by differentiated ratings of perceived exertion(overall RPE:RPEo, respiratory-metabolic RPE:RPEr, peripheral RPE:RPEp). Fifty-one young men, aged 18-26 years, were recruited as subjects. Mean(±SD)of VO_<2AT> and VO_2max, which were defined as criterion variables of cardiorespiratory fitness, were 27.1±6.8 and 50.3±7.0 ml/kg/min, respectively. During the submaximal GCT, the work rate(WR) was increased by 15 watts/min, and the scores of RPEo, RPEr and RPEp were recorded every one minute. Analyses of the data indicated that VO_<2AT> and VO_2max were significantly correlated with the WRs(r=0.33-0.69 and r=0.28-0.44, respectively)at which RPEo, RPEr and RPEp of 8 to 15 were first recorded(WR_, WR_, WR_;x=8-15). It was therefore accepted that WR_, WR_ and WR_ based on subjective perception during the submaximal GCT, could be useful for evaluation of cardiorespiratory fitness. Furthermore, we attempted to develop equations for predicting VO_<2AT> and VO_2max. Multiple regression analyses by the stepwise method using WR_, WR_, WR_, age, body mass and %body fat as the explanatory variables for predicting VO_<2AT> and VO_2max yielded the following equations. VO_<2AT>(ml/kg/min)=0.131 WR_(watts/min)-0.314 body mass(kg)-0.260 %body fat(%)+33.9 (R=0.869, SEE=2.9 ml/kg/min) VO_<2max>(ml/kg/min)=0.095 WR_(watts/min)-0.332 body mass(kg)-0.565 %body fat(%)-0.720 Age(yr)+83.1 (R=0.823, SEE=4.2 ml/kg/min) It was concluded that the submaximal GCT using RPEo, RPEr and RPEp was useful for evaluating cardiorespiratory fitness.