Isotopic compositions of S, Si and O of Precambrian BIFs at the North China Craton (NCC) are measured systematically. The 30Si NBS-28 values of quartz in BIFs of different types and ages are lower at large with most ranging from -2.0‰ to -0.3‰, similar to the δ30Si NBS-28 values of modern submarine black smoker and sinter. The δ30Si NBS-28 values of quartz contained in banded magnetite are lower than those of neighboring siliceous band for the same sample, while this goes the other way round for δ18O V-SMOW. The δ34S V-CDT values in the sulfides of BIF vary greatly from -22.0‰~+11.8‰, but mostly around 0.0‰. The Δ33S = -0.89‰~+1.2‰, showing an obvious mass independent fractionation feature. The Δ33S usually displays a negative value at the Algoma-type BIF closely related to volcanic activities, whereas a positive Δ33S value appears at Superior-type BIF distant from volcanic activity center. The isotopic component of Si and O imply that BIF was formed by submarine exhalation at early stage of the earth, whatever the Algoma-type or the Superior-type. SiO2 was precipitated at first to form the siliceous layer and Fe3O4 subsequently was deposited to form the magnetite layer during the marine exhalation process. A set of rhythmic layer stands for once marine exhalation activity and the periodic marine exhalations form regular rhythmic layers. The widespread BIFs and S isotope mass independent fractionation feature indicate a very low oxygen concentration in the atmosphere back then which may be less than 10-3 present atmospheric level, intense volcanic and marine exhalation activities, high temperature of sea water, a very high concentration of SiO2 and Fe2+, low pH value as well as a 3~5.5, and extremely low soluble sulfate concentration which may be less than 10-3 present soluble ocean sulfate. After 1.8Ga, the ocean sulfate concentration was increased, and the ocean was from iron rich to sulfate rich that is a decisive factor for the disappearance of the BIFs. The large scale volcanic activities and submarine exhalation greatly influenced the compositions and evolution of the ocean, and postpone oxidation time of the ocean for at least 600Ma compared with the atmosphere.