The mobile telecommunication service industry plays major role of the realization to the perfect information society in the 21st century and has a great influence in society and culture. The government has enticed the mobile company to keep up to make the mobile service fee low. In this situation, this paper estimates consumer surplus and price elasticity with on-line survey data from the consumer of mobile service. The total estimated consumer surplus of the market is reached to 6.43trillion won. The consumer surplus from SKT is estimated to 4.98trillion won and 1.66trillion won and 0.67trillion won was made by KTF and LGT respectively. The result also shows that consumer surplus is expected to be increased by the increase of the mobile service demand and the sales.