On January 28, the market price of phthalic anhydride in Jiangsu region fluctuated and consolidated. The mainstream negotiation price for ortho-xylene-based products was between 6,200 and 6,350 yuan/ton, while the mainstream negotiation price for naphthalene-based products ranged from 5,800 to 6,100 yuan/ton. Phthalic anhydride manufacturers maintained stable equipment operation, with the operating rate remaining low and steady. The domestic phthalic anhydride market had ample spot supply. The price of raw material ortho-xylene stabilized, while the price of industrial naphthalene consolidated. The support from rising production costs for phthalic anhydride weakened. Downstream plasticizer market prices fluctuated and rose, with plasticizer enterprises operating at stable 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 consolidate.