Most polysaccharides cannot dissolve in water but can be hydrolysed using hydrogen peroxide (H2O2) to yield a water-soluble product. This study presents a method of preparing water-soluble polysaccharides from peach gum by hydrolysis using H2O2. Extraction was monitored by the recovery rate. Factors affecting the hydrolysis of peach gum were investigated, and the optimum hydrolysis conditions were determined as follows: time, 8 h; temperature, 55°C; H2O2 concentration, 4% (v/v); and NaOH concentration, 2.0 M. The hydrolysates were filtered, neutralised with HCl, concentrated to ∼20% (w/v), precipitated with 5 volumes of ethanol, freeze-dried, and ground to yield a water soluble and white powder. The polysaccharide content of the product was 97.8%, and the yield was 83.6% (w/w).