A series of carbon-based solid acid catalysts are synthesized from bamboo through the approach of partial carbonization and sulfonation, where predecessor of the catalyst is activated by phosphoric acid in advance. After carbonization at 350 °C for 2 h and sulfonation at 105 °C for 4 h, the catalyst gained amorphous carbon structure with large surface area of 1208 m2 g-1 and strong acid density of 1.28 mmol g-1. The biodiesel yield reached 97.3% with the optimum esterification conditions. Due to the leaching of -SO3H groups, after fourth reused cycle of the catalyst, the biodiesel yield declines to 83.7%.