On January 9, the price of phthalic anhydride in Jiangsu region remained strong and stable. The mainstream negotiation price for ortho-xylene-based products ranged from 5,900 to 6,150 yuan/ton, while naphthalene-based products were quoted between 5,600 and 5,850 yuan/ton. The operating rate of phthalic anhydride plants decreased due to reduced equipment utilization. Despite sufficient spot supply in the domestic phthalic anhydride market, the cost pressure intensified as the price of raw material ortho-xylene fluctuated upward, and industrial naphthalene prices remained firm. Downstream plasticizer prices surged significantly, though the operating load of plasticizer enterprises declined. Demand for phthalic anhydride remained supported by rigid downstream procurement. It is expected that the phthalic anhydride market will stabilize with fluctuations in the near future.