On January 28, the market price of phthalic anhydride in East China fluctuated and consolidated. The mainstream quotation of phthalic anhydride by ortho-xylene method was 6,200-6,350 yuan/ton, while the market price of phthalic anhydride by naphthalene method was 5,800-6,100 yuan/ton. The price of industrial naphthalene fluctuated and stabilized, and the price of ortho-xylene also stabilized, leading to a steady cost of phthalic anhydride. The downstream plasticizer market experienced fluctuating increases, with plasticizer manufacturers operating at low and stable equipment utilization rates. Downstream demand remained rigid, and purchases of phthalic anhydride were primarily based on immediate needs. The demand support for phthalic anhydride persisted. However, the equipment utilization rate of phthalic anhydride manufacturers declined, resulting in a tightening supply of phthalic anhydride and low inventory levels. It is expected that the phthalic anhydride market will continue to fluctuate and consolidate in the near future.