Abstract: In order to investigate the influence of hydrocolloid on the cloud stability of cloudy apple juice, the composition of sediment of juice, characterizations of poplyphenols and protein in sediment were analyzed by using HCLP, SDS-PAGE and other analysis techniques, and the viscosity of juice adding hydrocolloid, the Zeta potential of particles in juice, the turbidity changing of juice adding hydrocolloid during 120 days storage were assayed. The sediment of juice was complicated and consisted mainly of proteins, carbohydrate, phenolic compounds (epicatechin, chlorogenic acid, tannin), 5-hydroxymethyl-furaldehyde (5-HMF). The sediment mainly formed by the assembling of original particles at the beginning of storage in juice. The cloud stability of cloudy apple juice would be more improved by adding 0.05% (w/v) CMC to juice. The cloud stability of juice containing CMC was improved by increased viscosity of juice and increased Zeta potential of particles in juice, and for juice containing guar gum, it was improved by increasing viscosity of juice.