The seasonal changes in trees are highly dependant on their health and growth rate. Monitoring the vigor of trees at every season provides basic data which can be used at trees planting to predict the physiological characteristics of their seasonal change. In this study, 3 kinds of trees; zelkova, camphor and metasequoia were monthly observed from April to December, using an infrared television camera. The vigor of the trees was evaluated in each season and the relationship between their image and the evaluation in each season was investigated. The data shows that there is a high correlation between the vigor and the seasonal evaluations.