Abstract: A simulated chewing machine was developed for evaluating in vitro the release behavior of nicotine from gum-based smokeless tobacco products, and the in vitro nicotine release rates from four kinds of gum-based tobacco products on the market were tested by combining that machine with HPLC. The chewing machine was mainly composed of a container for solvent, two peristaltic pumps, a thermostat, two circulating water tanks, a sample stage, an air compressor, a cylinder, a motor, a pneumatic clamp and a liquid collector. The test chamber formed by the circulation tanks and sample stage simulated a buccal cavity, which ensured nicotine release at a constant temperature of 37℃ into artificial saliva, the pneumatic clamp pushed by the air compressor compressed the test sample repeatedly simulating the chewing action. The in vivo and in vitro nicotine release tests showed that evaluating the release behavior of nicotine from gum-based tobacco products with the simulated chewing machine was simple and reliable, the test results were close to the nicotine release from gum-based tobacco products taken by a human being. The technique was of practical uses for the quality control of gum-based tobacco products, the evaluation of nicotine bioavailability as well as the control of nicotine.