The present invention relates to a chitosan capsule in which a soluble active ingredient is encapsulated in a matrix containing chitosan and phytic acid; a cross-linking method and materials capable of being used in preparing the capsule; and pharmaceutical, food and cosmetic compositions comprising the capsule. The chitosan capsule according to the present invention is prepared via ionic gelation of chitosan as a biodegradable polymer with phytic acid capable of rapidly and effectively forming a cross-linking reaction with the chitosan polymer. The capsule of the present invention shows high encapsulation efficiency for a soluble active ingredient and protects the soluble active ingredient from being damaged in a digestive tract, resulting in improving an in vivo delivery efficiency of a physiologically active material. Further, since the capsule of the present invention has a pH-dependent sustained-release mechanism which can minimize the release of a soluble active ingredient in the stomach and gradually release in the intestine, it is possible to regulate sustained-release of a soluble active ingredient.