Potential sports participants are one of the most important targets to be considered in the implementation of strategic marketing plans for promoting sports. The purpose of this study was to make clear a model that analyzes the sports population by analyzing the structure and characteristics of the potential market segment among walking participants, whose population is growing rapidly in Japan. The subjects of this investigation were one thousand people of over twenty years old, who were randomly selected in Tokorozawa-city. This study classified their segments of walking participation into four markets, continuous by active market, uncontinuous by active market, potential market, and non-interest market. This paper analyzed the characteristics of a potential market segment according to attitudes toward health, rate of participation in sports per week, and reasons of participation in sports. The numbers of respondents to the questionnaire were 483. The results are as follows: 1.This study found that over half of the subjects participated in walking. Classified into market groups these walkers showed rates of 39 .5%, 14.6%, 13.7%, and 32.5%, in the categories of continuous by active market, uncontinuous by active market, potential market, and non-interst market, respectively. 2.The differences of attitude toward health among people in the potential market were classified according to rate of participation in sports. As a result, it was found that the segment that did not participate in sports at least once a week tended to have a weak attitude toward health.