On January 30, the market price of phthalic anhydride in Jiangsu region fluctuated and consolidated. The mainstream negotiation price for ortho-xylene-based products was between 6,000 and 6,300 yuan/ton, while the mainstream negotiation price for naphthalene-based products was between 5,700 and 6,000 yuan/ton. The equipment operation of phthalic anhydride manufacturers remained stable, with the operating rate trending 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 declined, weakening the cost support for phthalic anhydride. The downstream plasticizer market experienced fluctuating price increases, with stable operating loads at plasticizer enterprises, maintaining some 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 weakly.