A novel three-branch optical power divider by Ti diffusion on lithium niobate is proposed and analyzed. For the conventional three-branch power divider, most of the optical power is transmitted to the central output waveguide and only little power is distributed to the two sideward output ones. Several designs have been proposed to increase the power in the two sideward output waveguides. Because they require extra regions of indices lower than that of substrate or higher than that of waveguide, it is difficult to find such indices for realizing their designs. In this work, we propose a novel three-branch optical power divider, which includes one substrate and waveguide, the realization of the proposed devices becomes very easy. Prior to the diffusion process, only one lithography step is required. For the proposed structure, the transmitted power in the two sideward output waveguides can be higher or lower than that in the central output one under a large branching angle. It is known that the index distribution in the Ti-diffused waveguide is varied with the diffusion process parameters. In order to understand the effect of waveguide fabrication parameters on power distribution in three output waveguides, the parameter variations are considered. Moreover, in comparison to the previous works, the proposed power divider has the advantages of low insertion loss, large branching angle, and easy fabrication.