Zinc hydroxystannate was widely used as green flame retardant and smoke suppression agent. In this paper, two different methods were used to prepare the nano-scale zinc hydroxystannate particles. The reaction of tin tetrachloride and zinc oxide was the first way. In the second method, zinc chloride reacted with sodium stannate. The reaction conditions were studied, and the products were characterized by TG/DTA, SEM, and XRD. The best experiment conditions to synthesis zinc hydroxystannate are using sodium stannate and zinc chloride as the raw material, reacting for an half hour at the temperature of 323K, and molar ratio of reactants of 1:1. This will get higher yield, more pure product with regular morphology.