Disclosed is a system and a method for setting an internal time corresponding to a standard time at a current location in a mobile station of an asynchronous scheme. The mobile station of the asynchronous scheme uses a Simple Network Time Protocol (SNTP), which is an application of a Network Time Protocol (NTP), allowing the mobile station to easily update internal time information using a synchronized time. The SNTP can provide a time value which can be used to accurately reset an internal time of the mobile station of the asynchronous scheme. By using the SNTP, the mobile station of the asynchronous scheme can obtain exact time information as in a CDMA network and update the mobile station's internal time with the time corresponding to an area in which a standard time is changed.