Controlling the genesis of ZnO micro-particles is desirable for tuning their morphologies. The OH-/Zn 2+ ratio has been correlated with morphologies showed in past research, but for different experimental procedures several morphologies have been synthesized for the same ratios. Then, the initial species distribution could serve better for predicting the final morphology than the OH-/Zn 2+ ratio. In this work, synthesis of ZnO micro-particles varying OH-/Zn 2+ ratios were conducted, and the initial species distributions were estimated based on the specific ion interaction theory. A significant correlation was observed between the initial species distribution and the final morphology in both, the current experimental results and results from the literature.