To provide a work flow system and a work flow processing method capable of deciding a person in charge of processing an activity in a simple system, and surely designating the processing for a work flow to a suitable person in charge of processing by each type of business defined by a work flow definition.

This work flow system is provided with a network for performing information communication, a plurality of input/output devices, a definition device, a work flow engine control device and a work flow data control device. The system is provided with a work flow definition means for defining the type of processing an activity, the processing order, and a user as a person in charge of processing the activity, a user definition means for defining the constitution of an organization to which the user as the person in charge of processing belongs, and a boss user of the user by each user, and a user decision means for uniquely deciding a person in charge of processing the next activity at the end of processing the individual activities.