On January 5, the price of phthalic anhydride in Jiangsu region rose strongly. The mainstream negotiation price for ortho-xylene-based products was 5800-6100 yuan/ton, while that for naphthalene-based products was 5500-5800 yuan/ton. The operating rate of phthalic anhydride plants increased slightly, leading to a rise in the overall operating rate. The domestic phthalic anhydride market had ample spot supply. The price of raw material ortho-xylene rose strongly, while the price of industrial naphthalene remained stable, resulting in increased cost support for phthalic anhydride. The downstream plasticizer market experienced a strong price increase, and the operating load of plasticizer enterprises declined, further strengthening the demand support for phthalic anhydride. Downstream industries maintained rigid procurement, and the phthalic anhydride market is expected to continue rising in the later period.