On January 15, the price of phthalic anhydride in Jiangsu region remained strong and stable. The mainstream negotiation price for ortho-xylene-based products ranged from 6,100 to 6,350 yuan/ton, while the mainstream negotiation price for naphthalene-based products ranged from 5,700 to 6,050 yuan/ton. The operating rate of phthalic anhydride manufacturers decreased, leading to a reduction in equipment utilization. The domestic phthalic anhydride market had ample spot supply. The price of raw material ortho-xylene fluctuated and rose, while the price of industrial naphthalene remained stable. The cost support for phthalic anhydride increased significantly. The downstream plasticizer market experienced a strong upward trend, but the operating load of plasticizer enterprises declined. Demand support for phthalic anhydride remained, with downstream industries making purchases based on rigid demand. In the later period, the phthalic anhydride market is expected to maintain a strong consolidation trend.