The novel solid acidic ionic liquid polymer has been synthesized through the copolymerization of acidic ionic liquid oligomers and divinylbenzene (DVB). The catalytic activities were investigated through the biodiesel synthesis from waste oils. The results showed that the PIL was very efficient for both the transesterification of triglycerides and esterification of free fatty acids with the yield of 99.0%. The procedure was quite simple with just one-step to complete both the reactions under mild reaction conditions. The high hydrophobic BET surface, high catalytic activities and high stability were the key properties of the PIL. (C) 2012 Elsevier B.V. All rights reserved.