On January 16, the market 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 plants decreased as manufacturers reduced equipment operations. 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. The downstream plasticizer market experienced fluctuating price increases, with plasticizer enterprises maintaining stable operating loads, providing continued demand support for phthalic anhydride. Downstream industries made purchases based on rigid demand. In the later period, the phthalic anhydride market is expected to stabilize.