On February 9, the market price of phthalic anhydride in Jiangsu region fluctuated downward. The mainstream negotiation price for ortho-xylene-based products ranged from 6,000 to 6,200 yuan/ton, while the mainstream negotiation price for naphthalene-based products ranged from 5,550 to 5,900 yuan/ton. The production equipment of phthalic anhydride manufacturers operated stably, with the operating rate remaining low but stable. 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, a downstream sector, also experienced fluctuating declines. Plasticizer enterprises maintained stable operating loads, leading to reduced demand support for phthalic anhydride. Downstream industries primarily engaged in rigid demand procurement. In the later period, the phthalic anhydride market is expected to experience weak consolidation.