alpha-AgBiS2 nanowhiskers have been prepared by a solvothermal method at 160degreesC. The characterized results showed that the product was alpha-AgBiS2 which was well crystallized as uniform nanowhiskers. The chain type structure of Bi-S compound under the circumstance of ethylenediamine was found crucial in the formation of alpha-AgBiS2 nanowhiskers in the possible mechanism.