A system which easily evaluates swallowing function is needed for the early diagnosis of deglutition disorder and the support for daily exercise for the purpose of its maintenance and recovery. We propose a method to measure laryngeal movement in a non-contact and non-invasive way with reasonable accuracy. To evaluate laryngeal elevation quantitatively, laryngeal prominence is detected from depth data by area extraction based on the classifier obtained by using a decision tree and optimum solution selection using species-based PSO. The elevation time and amount is calculated by tracking the laryngeal prominence. The laryngeal movement could be observed in persons with laryngeal prominence during water swallowing test.