The effluents from municipal wastewater treatment plant are believed to be a main water source of reclaimed water. However, the composition of organic matter in the effluents is unclear, which places a potential risk on the receiving waters body. Therefore, it is important to obtain the information on the composition and structure of organic matter in sewage plant, which will facilitate to improve the sewage treatment plants and to establishment the emission standard of harmful substances in wastewater effluent. Fourier transform infrared spectroscopy (FTIR) and three dimensional fluorescence excitation-emission matrix spectroscopy (EEM) were combined with second derivative infrared and fluorescence regional integration analysis to identify the composition and structure of particulate organic matter (POM) and dissolved organic matter (DOM) isolated from four sewage effluents (W1, W2, W3, and W4). The results showed that, POM in the effluents mainly consisted of aliphatic, aromatic, alkanes, carbohydrate and mineral salts, while DOM was primarily composed of carbohydrate, organic acid, proteins, peptides and hydrocarbons. As to POM in the effluents from the four sewage treatment plants, the sewage treatment plant W1 had higher aromatic substances and lower mineral salts; the sewage plant W2 had a higher carbohydrate content compared with the sewage plant W1; the sewage plant W3 had a higher aliphatic, protein and carbohydrate; and the sewage plant W4 was mainly composed of carboxylic acids and aromatic substances. As to DOM, W1 and W2 had a similar composition. The DOM in W1 and W2 comprised mainly the aromatic organic acid with high macromolecular, which accounts for 73.9% and 67.7% of the total DOM. However, W3 and W4 consisted mainly of proteins, peptides, carbohydrate and protein-like substances, which was responsible for 71.3% and 53.5% of the DOM. The results demonstrated that, FTIR spectroscopy coupled with second derivative analysis could be used to identify the main composition and structure differences between POM and DOM. EEM spectra combined with fluorescence regional integration can be applied to further quantitatively distinguish the composition differences of different effluent wastewater.