Tea (Camellia sinensis) is one of the most active and important biochemical sources. A number of factors, such as species, season, agronomic condition and age of the leaves, are known to affect the quality of tea. In this study, fresh tea shoots consisting of one apical bud and two adjoining leaves were collected from Tea Research Institute of Iran (Lahijan). Some of the phenolic components of two clones of tea (100 and 451) + in three harvest seasons (spring, summer and autumn) were investigated. The results indicated that harvesting time was crucial in determining the biochemical compounds of tea clones, so that antioxidant activity was increased in both examined colons from 1st harvest (spring) to 3rd harvest (autumn), showing some of the impact of ecological factors in different seasons on the biochemical compounds of tea and helping to find oppropriate time to obtain tasty tea during three harvesting season.