On January 6, the price trend of phthalic anhydride in East China showed an upward movement. The mainstream quotations 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 and stabilized, while the price of ortho-xylene rose strongly, leading to an increase in the cost of phthalic anhydride. In the downstream market, the plasticizer sector experienced a robust price increase, with plasticizer manufacturers reducing their equipment operating rates. Downstream demand remained rigid, and procurement of phthalic anhydride was primarily based on immediate needs. Despite this, demand support for phthalic anhydride persisted. Phthalic anhydride manufacturers slightly lowered their equipment operating rates, but supply remained sufficient, and inventory levels were low. It is expected that the phthalic anhydride market will experience strong consolidation in the near future.