Provided is a mobile terminal and a system scan method thereof for effectively acquiring system information. The system scanning method includes performing a first scanning process on entire channels registered to a Preferred Roaming List (PRL) for acquiring system information, calculating, when the system information is not acquired in the first scanning process, a power saving time and a secondscan time on the basis of a first scan time taken for the first scanning process, the second scan time being equal to the first scan time, and performing a second scanning process and a power saving process, on the basis of the power saving time and the second scan time, alternately until the system information is acquired.