Comparative study has been done on the components of Pu’er tea and Fu-brick tea with the identified components of black tea by LC-MS. Result shows that Pu’er tea and Fu-brick tea, which belonged to the Dark tea group, had the similar UV chromatography, it means that they have some similar compounds. However they are different from black tea as they have not typical peaks of theaflavin and thearubigin at the 380βnm. The way to study the black tea might not be suitable for dark tea. Some components can be found by MS, however, they can not be identified in UV picture as their contents are too low.