Abstract: Nicotinic acid is an important intermediate for pharmaceuticals and fine chemicals，and it is estimated that the domestic demand will exceed 5000 tons by 2010. In this paper，nicotinic acid was prepared by subliming amd decarboxylation of pyridine-2，3-dicarboxylic acid (quinolinic acid) which was obtained from the ozonolysis of quinoline in a solvent containing glacial acetic acid，acetic ether and water under mild reaction. Through the experiment，the influences of concentrated sulfuric acid and solvents on the yield of nicotinic acid were investigated. The optimum molar ratio of n(concentrated sulfuric acid)︰n(quinoline)=（1.1～1.5）︰1；V(glacial acetic acid)︰V(acetic ether) = 3︰1. Under the above conditions the yield of pyridine-2,3-dicarboxylic acid was up to 66%. Nicotinic acid was obtained by decarboxylation of pyridine-2,3-dicarboxylic acid with a yield of more than 96% and the melt point was 235～237.3℃. The relative mass fraction was no less than 95% detected by HPLC.