Describes a computer vision system to locate a human face in an image sequence. The system operates on an image sequence captured during a time period and locates the human face region on each image in the sequence. It is the first important step in a human face recognition system. In this system we use a genetic algorithm to construct human face templates. We evolve our templates to adapt to the characteristics which human faces commonly have. The system consists of the following image processing modules: (1) noise reduction, (2) moving object region detection, (3) human face candidate region detection, (4) human face region verification. In the last step, we confirm the human face region among the candidate regions using the human face templates constructed by the genetic algorithm.