Abstract: To reduce the tobacco-specific nitrosamines (TSNAs) in oral tobacco products, under laboratory conditions, a small amount of activated carbon (AC) particles were uniformly spread and dispersed on the surface of tobacco powder on the basis of the stickiness increase of tobacco surface after moistening. The effectiveness of this in situ adsorption method to reduce TSNAs in tobacco was verified by the simulation of production process, and the results showed that the adsorption rate of TSNAs in oral tobacco by the AC particles was promoted by the increasing AC amount, reduced AC particle size, a modified AC with zinc oxide, an increase in the moisture content of the raw tobacco, or prolonged contact time between the added AC and tobacco powder. The results suggested that when the tobacco moisture content was about 40%, 26.9% of TSNAs in the oral tobacco products was adsorbed after adding 4%(mass fraction)of a coconut shell derived AC with 400 meshes(0.037 mm)particle size. This method is simple in operation, tobacco powder remains its original shape after being wetted. Besides, the coconut shell AC is of no cytotoxicity and easy to obtain with a small addition amount, thus has the potential to combine with the existing oral tobacco production process.