Organmontmorillonite(O-MMT) was modified by surfactant-octadecyltrimethylammonium bromide with Na-montmorollonite(Na-MMT).The characteristics and structure of the sorbent were investigated by Fourier transform infrared ray spectroscopy(FT-IR),X-ray diffraction(XRD),transmission electron microscope(TEM) and BET analysis.The results indicated that organic cations were exchanged into Na-MMT’s stacks and the basal spacing(d001) increased from 1.26 nm to 3.80 nm.Then O-MMT was used as sorbent to treat oily wastewater from port.Comparing to Na-MMT,the COD(chemical oxygen demand) and oil removal increased by 5.0 times and 2.5 times,respectively .The effects of agitation time,the amount of O-MMT and recycle times of O-MMT were investigated and the optimum experiment condition at room temperature was established: adding 2.0 % O-MMT and agitating 30 min.The duty-cycle operation of O-MMT was three times.