On January 15, the market price of phthalic anhydride in East China showed a strong consolidation trend. The mainstream quotations for ortho-xylene-based phthalic anhydride were in the range of 6,100–6,350 yuan/ton, while the market price for naphthalene-based phthalic anhydride was between 5,700–6,050 yuan/ton. The price of industrial naphthalene fluctuated and stabilized, while the price of ortho-xylene fluctuated and increased, leading to higher production costs for phthalic anhydride. The downstream plasticizer market experienced a strong upward trend, with plasticizer manufacturers maintaining stable equipment operating rates. Downstream demand remained rigid, and procurement of phthalic anhydride was primarily based on immediate needs, providing continued support for demand. Phthalic anhydride manufacturers maintained weak but stable equipment operating rates, ensuring sufficient supply. Phthalic anhydride inventories remained low. It is expected that the future market for phthalic anhydride will continue to exhibit a strong consolidation trend.