A method and apparatus for monitoring a human activity pattern irrespective of the wearing position of the sensor unit by a user and a direction of the sensor unit are provided. The method for monitoring an inertia movement signal according to a movement of a user using a sensor unit attached to the user; detecting a direction of the sensor unit from the inertia movement signal; detecting a wearing location of the sensor unit by using acceleration and direction; determining the activity pattern of the user from inertia sensors; and delivering physical activity data corresponding to at least one caloric consumption, number of steps, and movement distance.