The pectin content of tea leaves was determined. by the colloidal titration method and the following results were obtained.
1. The insoluble pectin did not transformed into soluble pectin (S) on the steaming.
2. In young sprout, the content of total pectin (T) was little and S was much, but in old leaves, T increased and S decreased.
3. On the same season, the content of T increased and S decreased in the lapse of time.
4. In the first plucking season, the content of T was much more than in another seasons but the content of S seemed to be less changed.
5. The content of T in green tea varieties was much more than the one of black tea varieties.
From the above mentioned results, it was found that the younger the leaves, the more the content of T decreased and S/T ratio increased and the pectin number. (S/T²×1000) was, therefore, seemed to bed a good indicator for the quality of tea leaves.