A psychological experiment was conducted to estimate probability weighting function whose stimuli were graphically presented. We conducted a modified experiment of Wu and Gonzalez (1996) study by using graphical representation of lotteries. The experiment consisted of 240 binary choices between two gambles. Participants were forty-four members of undergraduate students and graduate students in Waseda University. We fitted the choice data with probability weighting functions proposed by Tversky and Kahneman (1992) and Takemura (1998, 2001). We used the same procedure of Wu and Gonzalez (1996) study for estimating the parameters of both functions and computed Akaike Information Criterion (AIC), which indicated goodness of fit. The choice data confirmed previous findings of risk attitudes (Tversky and Wakker, 1995, Wu and Gonzalez, 1996) in losses. However, the choice data indicated previous findings of risk attitudes (Tversky and Wakker, 1995, Wu and Gonzalez, 1996) in only high probability in gains. Our estimates of Tversky and Kahneman's (1992) function were more linear than the estimates of Wu and Gonzalez (1996). The AIC of Tversky and Kahneman's (1992) function and Takemura's mental ruler model (1998, 2001) indicated that the Takemura's mental ruler model (1998, 2001) fitted better than the Tversky and Kahneman's (1992) model.