This study analyzed the influence of major factors on KTX and SRT high-speed railway users, focusing on Gyeongbu high-speed line. First, the results of analyzing the long-term balance relationship through the VECM model showed that the common point is that when the seat supply, gross domestic product and household disposable income increase, the number of high-speed railway users increases, and when the weighted average oil price rises, the number of high-speed railway users decreases. However, the difference was that when seat supply and gross domestic product increased by 1%, the number of SRT users increased larger than that of KTX users. Second, the impact response function and the prediction error dispersion analysis result showed that KTX users were affected by about 35% of seat supply, gross domestic product and disposable income per household while SRT users were affected by about 12.1%, which is relatively low compared to KTX users. In the meantime, this study suggests that KTX needs various marketing strategies such as additional discounts and improvement of mileage accumulation methods to overcome the difference of fare rates which is 10% higher than SRT in order to secure fixed demand for high-speed railway users.