In recent years, research on earlier life and the concurrent environment becomes a hot topic of geosciences. The study of biomarkers plays a more and more important role on the research of earlier life and the concurrent environment. Biomarkers detected from Precambrian include normal and branched alkanes, cyclohexylalkanes, adamantanes, acylic isoprenoids, tricyclic terpanes, hopanes, and a diverse range of steranes and carotenoids. Different biomarker has different biological precursor and indicates different environment. Biomarker analysis can provide critical clues for their precursor composition and diagnostic tools for their environmental interpretation. Known biomarker assemble indicates that oxygen generating cyanobacteria and eukaryotes might exist 2. 7Ga ago. However, the ocean remains oxygen deficiency and organisms are dominated by prokaryotes during Paleo and Mesoproterozoic. The existence of Cyanobacteria in the Archean did boost the atmospheric oxygenation and make eukaryotes be present, but the retention of oxygenation in ocean obviously restrains the development of eukaryotes, leading slow organism evolution in the long period of 2. 0 Ga between 2.78 Ga and 0. 6 Ga.