Abstract: p-Isopropylphenol of high purity was synthesized from β-pinene through a three-step sequence of oxidation,ring-opening and dehydrogenation.The overall yield was 31%.Factors affecting ring-opening and dehydrogenation had been discussed.It was found that the ring-opening of nopinone with 40% phosphoric acid was well performed at 80℃ for 1 h and the yield was 67.9%.The dehydrogenation reaction was well done under sealed condition and the yield was 63%.