Abstract: OBJECTIVE To establish the quality standards for xanthane hydride. METHODS The xanthane hydride was identified by thin layer chromatography(TLC), and its purity was determined by HPLC. RESULTS The TLC spots were clear and specific. The HPLC method results showed that, the degree of the separation between xanthane hydride and the next impurity was >1.5. The precision and repeatability were 0.72% and 1.04%, respectively. The loss on drying was less than 3% and the residue on ignition was lower than 0.5%. CONCLUSION A quick, easy and accurate method was established and used in the process of oligonucleotides synthesis.