A human computer interaction system and a human computer interaction method are provided. The human computer interaction system includes a first sensor, a second sensor and a processor. The processor obtains first motion sensing data of the first operating portion from the first sensor, obtains second motion sensing data of the second operating portion from the second sensor different from the first operating portion, and determines an event according to both the first motion sensing data and the second motion sensing data. Accordingly, a hybrid motion tracking method for multiple operating portion of the user is provided.