On February 5, the price of phthalic anhydride in Jiangsu fluctuated downward. The mainstream negotiation price for ortho-xylene-based products was 6,000–6,200 yuan/ton, while that for naphthalene-based products was 5,550–5,900 yuan/ton. Phthalic anhydride production facilities maintained stable 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 fluctuated downward, weakening the cost support for phthalic anhydride. The plasticizer market also experienced a downward fluctuation, with plasticizer enterprises maintaining stable operating loads, resulting in reduced demand support for phthalic anhydride. Downstream industries adopted a rigid procurement approach. In the later period, the phthalic anhydride market is expected to consolidate weakly.