With tea plants of keemenzhong as reporters,tea caffeine synthase dsRNA(dsTCS) was transferred into 500 flowers of receptors through pollen-tube pathway.Forty-three seeds from transferred receptors and 38 plants were obtained.With seed-setting rate of 8.6%,15 of treated tea plants which were transferred into dsTCS and 5 untreated tea plants were selected,with 2 seeding leaves cut from the same segment of each plant for the measurement of caffeine.The result is the proportions of caffeine in all of the 15 single tea plants are lower than that in the untreated ones,with the most obvious one lower by 44.01%,which proves that transformed dsTCS refrain the synthesis of caffeine in tea plants.