High effective acidic transesterification catalyzed by trifluoroacetic acid for biodiesel production was studied in the present research. The results showed that the oil could be converted to biodiesel directly by one-step trifluoroacetic acid catalyze process without extreme temperature and pressure conditions. The optimum process combination was 2.0 M catalyst concentration with 20:1 M ratio of methanol to oil at temperature of 120 degrees C. It reduced product specific gravity from an initial value of 0.965 to a value of 0.878 in about 5 h of reaction time, and the methyl ester content reached as high as 98.4%. The present procedure represents a simple and mild method for biodiesel production in short reaction time and with high conversion rate, which would offer potential for an industrial process. (C) 2009 Elsevier Ltd. All rights reserved.