The composition of the flowback fluid was complex and it is difficult to characterize the organic matter content. The hydroxypropyl guar gum, which is the main components of fracturing fluid was chosen as the research project, the effect of the content of organic matter and cholrine ion, oxidation treatment on the identification of the organic matter content of fracturing liquid were investigated by measurement of chemical oxygen demand(COD) and total organic carbon (TOC), respectively. The results showed that there was larger limitation when using COD method to characterize liquid organic matter content of fracturing fluid, while TOC was more suitable to charaterize the content of the organic matter of hydroxypropyl guar gum solution.