This experiment was conducted to synthesis the dihydromyricetin-nickel complex (DMY-Ni) and clarify the feeding safety of DMY-Ni as a feed additive. DMY-Ni was prepared by the heating reflux method with dihydromyricetin (DMY) and nickel acetate as the materials. The complex was characterized by ultraviolet (UV) spectra and infrared (IR) spectra. DMY and DMY-Ni were used to study the effects of different concentrations (10, 20, 40, 80 and 160 μg/mL) and different action time (12, 24, 36 and 48 h) on the proliferation of normal liver parenchymal cells AML12 for mice by MTT method. The results showed as follows:the complex which was synthesized by DMY and nickel ion was confirmed as DMY-Ni. The survival rate of AML12 cells which were treated by 10, 20 and 40 μg/mL DMY or DMY-Ni for 48 h was not significantly different compared with the blank control group (P>0.05). After treatment for 48 h, the survival rate of AML12 cells of DMY-Ni group of 80 μg/mL and above was significantly lower than that of the blank control group (P<0.01 or P<0.001), and the survival rate of AML12 cells of DMY group of 160 μg/mL was significantly lower than that of the blank control group (P<0.01). And the survival rate of AML12 cells was gradually decreased with the increase of the concentration of DMY or DMY-Ni and the extension of the action time. Half the inhibitory concentrations (IC₅₀) of DMY and DMY-Ni on AML12 cells were 285.10 and 222.84 μg/mL, respectively. In conclusion, DMY and DMY-Ni have relatively low toxicity to AML12 cells, and the toxicity to AML12 cells of DMY-Ni is slightly increased compared with DMY.