| The optimum safe interval period and the most reasonable and effective methods of degradation were investigated in this paper which were based on researching the dynamic trends and degradation technique of pesticide residue in tea, aiming to reduce the contents of pesticide residue. At the same time, the change of contents of biochemical components and aroma were studied, investigating the influence of pesticide on the quality in tea. The results of researching showed as followed:1．The speed of degrading Bifenthrin, Endosulfan, Dichlorvos and Buprofezin in tea plants ranked first, then the speed tended to be decreasing and moderating with the process of time, and the dynamic trends of residue were basically conformed to first-order dynamic equation.2．Processing contributed to the degradation of pesticide residue. The amounts of pesticide residue in dried tea were reduced by over 60%, and in tea infusion were less, which ranged from 12% to 25%. The phrase of reducing pesticide in the processing tea was at drying mostly in that high temperature accelerated the degradation of pesticide residue.3．Among these four pesticides, we found that the higher the concentrations were sprayed, the earlier the time of plucking after spraying came, and the higher the residues in tea samples were. Bifenthrin, Endosulfan and Dichlorvos reached the MRL standards after 7 days, that is, the pesticide residue in tea plucked during the sate interval period did not exceeded the standards, and conformed to the new standards prescribed by E.U. and "Positive List System" prescribed by Japan. Buprofezin was sprayed according to concentration limits and met the MRL only when plucking tea leaves after 14 days.4．We also found that different methods of firing had distinct influence on pesticide residue in tea. The effects of firing showed that liquefied firing ranked the best, microwave firing the second, and steam firing the last relatively, which may be related to the temperature of firing because the temperature of steam firing was the lowest among these three methods.5．Spraying leaf-based residue degradation preparations also contributed to pesticide residue degradation. As for Bifenthrin, Endosulfan, Dichlorvos and Buprofezin, after spraying leaf-based residue degradation preparations, the pesticide residue in tea were lower than comparisons; and the effects of degradation had remarkable difference between hydrogen peroxide and sodium bicarbonate.6．The influence of different heating treatments on pesticide residue showed that far infrared heating was more effective than microwave heating; drier heating was the least effective relatively. The same heating method in the same heating time, in certain scale, whether far infrared, microwave or drier, the higher the temperature raised the more effective the method was. Results showed that the best parameters of technics were oven of the temperature 140℃with 1min , microwave at middle power level with 4 min and far infrared of 100℃with 1h respectively.7．The influence of spraying Bifenthrin, Endosulfan, Dichlorvos and Buprofezin on quality showed that in pesticide-sprayed tea plucked after 3 days and 6 days, the biochemical contents had distinct difference, and water extract, tea polyphenol, flavonoid, catechin and theine were lower than that treated by comparison (treated by water), and the content of biochemical had remarkable difference between picking after 3 days and picking after 6 days, that is, the contents in tea had been reduced after spraying pesticide, so after spraying some of pesticides could debase the quality of tea.8．Spraying pesticides had strong influence on the aroma of tea, and the contents 1,6,10-Dodecatrien-3-ol, 3,7,11-trimethyl-, (E)-,à -Farnesene distinctly increased .
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