On January 9, the market price of phthalic anhydride in East China showed a strong consolidation trend. The mainstream quotation for phthalic anhydride produced via the ortho-xylene method ranged from 5,900 to 6,150 yuan per ton, while the market price for phthalic anhydride produced via the naphthalene method was between 5,600 and 5,850 yuan per ton. The price of industrial naphthalene fluctuated but tended to stabilize, while the price of ortho-xylene experienced a fluctuating increase, leading to a rise in the production cost of phthalic anhydride. Downstream, the plasticizer market saw a strong upward trend, with plasticizer manufacturers reducing their equipment operating rates. Downstream industries maintained rigid demand for procurement, with phthalic anhydride being purchased mainly on an as-needed basis. Demand support for phthalic anhydride remained, while the operating rates of phthalic anhydride manufacturers slightly declined. Supply of phthalic anhydride was sufficient, and inventory levels were low. It is expected that the phthalic anhydride market will continue to show a strong consolidation trend in the near future.