Abstract: OBJECTIVE To establish a new method for the dissolution curve determination and related substance of oxycodone hydrochloride extended-release tablets,and evaluate the comparability of dissolution curve and the related substances of the self-made oxycodone hydrochloride extended-release tablets and the original drug. METHODS The dissolution curves of two preparations in four media, including water, hydrochloric acid(pH 1.2), acetate buffer solution(pH 4.0) and phosphate buffer solution(pH 6.8), were made, and their similarity was evaluted by similarity factor. The chromatographic conditions of the related substances were optimized and the baseline separation of 14-hydrocodine ketone and hydrocodone was achieved. The related substances of self-made oxycodone hydrochloride sustained-release tablets and reference preparetions were compared and the impurity profile was studied. RESULTS The similarity factor of the release curves of the self-made drugs and the original drugs in four release mediums was>50, which indicated that the release behavior of the two preparations in vitro was similar, and the mass spectra of the related substances of the two preparations were basically the same, indicated that the quality of the two preparations was basically the same. CONCLUSION The established release curve and determination method of related substances are accurate and reliable, which can provide reference for the consistency evaluation of generic drugs for oxycodone hydrochloride extended-release tablets.