The present invention is to provide a mobile communication terminal with a GPS function capable of further varying the positioning performance of each positioning mode preinstalled in the terminal. A GPS positioning section of the mobile communication terminal with the GPS function can perform positioning in a plurality of positioning modes using the A-GPS system. When a GPS control section of the mobile communication terminal with the GPS function causes the GPS positioning section to perform positioning, the GPS control section sets a positioning mode in the GPS positioning section, varies an allowable error of a communication synchronizing clock established between the terminal and a base station as a parameter relating to the positioning performance of GPS positioning based on the A-GPS system in which a fixed value has been conventionally used, and sets the allowable error in GPS positioning means.