An experimental investigation was carried out on microfiltration of oil-in-water emulsion using the coal-based carbon membrane prepared by carbonization of tubular precursor through extrusion method. Experimental results show that coal is a good precursor for preparation of the carbon membrane, and treatment of oil-in-water emulsion using the carbon membrane is feasible and effective with the oil rejection efficiency being over 98%. Based on the modified Hermia's model, membrane fouling mechanisms were analyzed and resistance controlling factors of permeate flow were discussed. Under the present operating conditions, there is a switch of fouling mechanisms from the standard pore fouling to the cake filtration at small apparent flow rate and trans-membrane pressure difference. When the values of two parameters are raised, the intermediate pore fouling becomes dominant after the early period of cake filtration. (C) 2007 Elsevier B.V. All rights reserved.