Abstract: In order to achieve effective utilization of processing by-products from different tea,the chemical compositions of tea sifting,tea dust,tea stem and bulk tea from green tea,oolong tea and black tea were analyzed and compared. The results showed that green tea was non-fermented tea,the catechins content of its sifting and dust was higher than other tea and by-products,it was similar or even higher than the bulk green tea,which content were 19.34% and 18.52%,the green tea stem had higher contents of amino acid and total sugar than other tea by-product and bulk tea,which were 2.65% and 22.85%. Black tea was fermented tea,there were more theaflavins and theasinensins in tea dust,tea sifting and tea stem,black tea dust had the highest content of theaflavins,theasinensin A and theasinensin B,which were 0.96%,1.65% and 0.53%. Oolong tea was semi-fermented tea,the catechins,TFs,TSs content of Oolong tea were between green tea and black tea,the amino acid of oolong tea were lower than green tea and black tea. The present research showed that the tea polyphenol,water extract,total sugar,soluble protein,caffeine,amino acid and catechin composition content in tea dust and tea sifting had the similar value or even higher than bulk tea,the tea stem had high content of total sugar and amino acid,which value was higher than bulk tea,this paper provided a theoretical basis for the further research and development of tea processing by-product after these chemical compositions were clear.