BACKGROUND: Biodiesel is a green, safe, renewable alternative fuel, which could partly solve the problem of energy shortage and environmental pollution. Heterogeneous catalysis is an economically and ecologically important process because catalysts have many advantages: noncorrosive, environmentally benign and fewer disposal problems. They are also much easier to be separated from liquid products and can be designed to give higher activity and longer catalyst lifetimes. This work aims to develop a novel approach for biodiesel production from soybean oil by using heterogeneous catalyst. RESULTS: A series of solid base catalysts were prepared from the support attapulgite (ATP) loaded with potassium carbonate by an impregnation method. The optimal catalyst preparation conditions were 400 degrees C calcination temperature and 4.2:1 molar ratio of K:ATP. When transesterification reaction was carried out with a molar ratio of methanol to oil 22: 1, a reaction time 3.0 h, a reaction temperature 60 degrees C and catalyst amount 8.0%, the highest biodiesel yield reached 93.4%. The catalyst has longer lifetime and maintained sustained activity after being used for five cycles. CONCLUSIONS: The prepared heterogeneous catalyst had high catalytic activity for the transesterification reaction. The properties of biodiesel make it a realistic fuel as an alternative to diesel. (C) 2013 Society of Chemical Industry