UV-curable inkjet ink is composed of pigment particles, prepolymer, monomers, photoinitiators and various additives. The photoinitiators have important influence on the curing performance of UV-curable inkjet ink. With the aim to study the impact of the photoinitiators on the curing rate and energy of UV-curable inkjet ink, based on the formulation design principle, three photoinitiators such as TPO, TX, 907 were chosen and seven kinds of inks were prepared. The rheological behavior was tested during the curing process when they were irradiated by Ultraviolet. According to the rules that the elastic modulus G′ and viscous moduli G″ changing with the curing degree of the ink sample, the method evaluating the curing rate of UV inkjet ink using rheological parameters was studied. The results suggest: the time for the appearing of the gel was shorter using the photoinitiators including 907 and ITX and the ink was cured fast. The photoinitiators including 907 and ITX lead to good curing properties for our prepared ink.