PURPOSE: To provide the call origination regulating system for mobile communication system with which call origination regulation can be easily performed for preventing a portable telephone set or the like from being illegally used by the other person of a mobile station.

CONSTITUTION: Corresponding to the input of a user, a telephone number excepting for any specified speaking party registered by a number setting means 22 is recognized by a code recognizing means 25. When it is detected by comparing a registered number with a call originating number while using a call originating number comparing means 24 that a call is originated with this recognized telephone number, its speaking time is measured by a time measuring means 23. When this measured time gets longer than the time set by a time setting means 21, a call origination regulating part 13 regulates the call origination to disable it.