On January 13, the price of phthalic anhydride in Jiangsu remained strong and stable. The mainstream negotiation price for ortho-xylene-based products was between 6,100 and 6,350 yuan/ton, while that for naphthalene-based products was between 5,700 and 6,050 yuan/ton. The operating rate of phthalic anhydride plants decreased as manufacturers reduced production. The domestic phthalic anhydride market had sufficient spot supply. The price of raw material ortho-xylene fluctuated and rose, while the price of industrial naphthalene remained strong and stable. The increasing cost of phthalic anhydride provided stronger support for its price. The downstream plasticizer market remained strong and stable, with plasticizer enterprises reducing their operating load. However, demand for phthalic anhydride continued to be supported, with downstream industries making purchases based on rigid demand. In the later period, the phthalic anhydride market is expected to remain strong and stable.