The purpose of this study was to find a suitable standard height of the lavatory in public spaces through the review of relevant regulations, questionnaire survey, lab works, and experiment to measure lavatory heights. The results of the study were as follows: First, the heights of the current public lavatory were ranged from 68cm to 89cm, and the heights to the faucet were from 71cm to 91cm. The recent lavatory was more likely to be higher in heights. Secondly, the suitable height for public lavatory was ranged from 55% to 65% of the heights of the participants put on shoes. Thirdly, 90cm lavatory in height was considered to be more suitable to use for the majority than was 83cm lavatory. Fourth, the author suggest that the suitable y(lavatory height)=77.818 + 0.117x(put on shoes heights). This study suggested that adopting 95% range, the most suitable height of public lavatory is more than 90cm high for the people whose heights are more than 150cm.