People can acquire products and services by paying price and other resources including time. People wait on line for purchasing many goods and services. Time is a important resource. As such, consumer have to make a decisions regarding their use of time in the purchase and consumption of services. The view that time as a resource is comparable to money is common in many approaches to the study of time. An economic interpretation might be that the value of one’s time can be expressed in monetary terms as an opportunity cost, often represented by one’s after-tax wage rate. In economics, an individual's hourly wage rate is a commonly used benchmark for one’s opportunity cost, and accordingly one should be indifferent between paying hourly wage rate in cash and spending an hour of time working in order to acquire a service. But a key difference between temporal and monetary currencies is that the opportunity cost of money is easy to assess, whereas the opportunity cost of time is more ambiguous. Time and money differ because money is readily exchangeable and it is fairy constant across situation, but time is not readily exchangeable and it is perishable. While waiting time research has implicitly assumed customers incur high waiting costs during waiting in line, few studies have explicitly measured the cost(value) of waiting time. This study examined the relationship between the value of time and the reservation price in purchasing a service. The purpose of this study is twofold: First, this study tries to estimate one’s value of time in terms of monetary value. In this study, we introduce a procedure to measure the value of time based on a consumer survey by a conjoint measurement. We estimate individual's value of time from exchange value(trade off) between time and money. Secondly, it is to show that the monetary value of time is different among segments which are divided by the importance rate of the time and price. And the differences of the time value and price elasticity among segments are compared. A conjoint measurement of time value is developed in Korea gasoline market which is composed of four major companies. Four service attributes such as brand name, price, total supply time, and promotional service factors are reported as choice factors from the secondary data. 4×4×4×4 fractional factorial design is set up originally. Through the asymmetrical orthogonal array, the final 16 profiles are used for full-profile stimulus cards method. 134 car owners are participated in conjoint experimentation and this data was analysed using OLS regression method. The importance of attributes and individual price response function were calculated using logit choice model. These are the major results of this study ; 1) The importance rate of each attributes is 58.4% of price, 33.9% of time, 4.0% of promotional service and 3.07% of brand. 2) The average time value of respondents was 7,945 Won per hour. Deacon and Sonstelie(1985) estimated the value of time spent waiting in US. They analyzed data from a natural experiment with rationing by waiting. In Their study, US customers waited in line an average of 14.6 minutes for saving $0.185 per gallon. This is monetary value of about 7,597 Won per hour. The two figures are so analogous. 3) The statistical result of our study on the relationship between individual time value and individual hourly wage rate was not significant. This is also very similar to Doacon and Sonstelie’s study. The result of two countries helped to strengthen the limitation of wage rate to represent one’s opportunity of time. 4) Respondent were segmented by the importance of attributes. The time value and reservation(optimal) price are significantly difference between two segments but there was not significant difference on hourly wage rate.