Waterless offset doesn't use dampening solution, so it has the advantage of color saturation that the water offset can not reach. Monomer is an important component of the UV waterless offset ink; it has great influence on the performances of ink. Ink samples were made separately by using different monomers. The flow curve, thixotropy crack index, surface tension, gloss, curing speed and other performance parameters of the ink samples were tested, and the influence of different kinds of monomer on the performance of ink was analysised. The results show that the viscosity of monomer affects the viscosity of ink sample directly; six monomers we used have good curing speed; the lowest surface tension can be got when using monomer with single functionality; and six ink samples have large thixotropy. The result of the compound EOEOEA, TPGDA and TMPTA is 0∶3∶7 by using the functionality design principle.