Abstract: The suspension culture of callus obtained from tender leaves of Camellia sinensis were conducted with MS added to IBA 2βmg/L, 6-BA 4βmg/L and ethyl-amine 25βmmol/L in a fermenter. The effects of different medium composition on the growth of tea cell and the amount of synthesized theanine were analyzed. The orthogonal design was utilized in the experiment. Results showed: both the growth of tea cell and the theanine accumulation reached its peak at19^th~20^th in the whole cultrue cycle. Both growth of the cells and the amount of theanine would present an optimal increment (16.33βg/100βml and 3.357βg/100βml), when the medium mixed with NH₄⁺/NO₃^- 1.0/60.0βmmol/L, K⁺ 100.0βmmol/L, Mg²⁺ 3.0βmmol/L, H₂PO₄^- 3.0βmmol/L, sucrose 30.0βg/L and protein 2.0βg/L. The logarithmic phase and the stationary phase were enhanced and the theanine accumulation was increased, when the amount of protein hydrolysate was raised in the medium. The increasing rate of tea cell growth and theanine accumulation was influenced by the different amount of H₂PO₄^- in the medium. the growth of tea-cell was not significantly effected by both K⁺ and sucrose, but it was significantly effected by Mg²⁺. The activity of theanine synthetase（L-glutamate: ethylamine lingase）was significantly effected by NH₄⁺/NO₃^-. The optimal culture-time should be ranged from 19~22 days in a culture cycle.

Key words: theanine, Camellia sinensis(L.)O.Kuntze, suspension culture, biosynthesis