On January 4th, the market price of phthalic anhydride in East China showed an upward trend. The mainstream quotation for phthalic anhydride produced by the ortho-xylene method was between 5,800 and 6,000 RMB/ton, while the market price for phthalic anhydride produced by the naphthalene method ranged from 5,500 to 5,750 RMB/ton. The price of industrial naphthalene fluctuated and tended to stabilize, while the price of ortho-xylene rose strongly, leading to an increase in the production cost of phthalic anhydride. The downstream plasticizer market experienced a strong upward trend, with plasticizer manufacturers reducing their equipment operating rates. Downstream demand remained rigid, with procurement of phthalic anhydride primarily based on immediate needs. The demand support for phthalic anhydride persisted, while the operating rates of phthalic anhydride production facilities slightly declined. The supply of phthalic anhydride remained sufficient, and inventory levels were low. It is expected that the phthalic anhydride market will experience strong consolidation in the near future.