On February 4, the market price of phthalic anhydride in Jiangsu region fluctuated and declined. The mainstream negotiation price for ortho-xylene-based products was between 6,000 and 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, and the operating rate remained low and steady. The domestic phthalic anhydride market had ample spot supply, with the price of raw material ortho-xylene stabilizing and the price of industrial naphthalene fluctuating downward. The cost support for phthalic anhydride weakened. The downstream plasticizer market experienced fluctuating declines, and the operating load of plasticizer enterprises remained stable, leading to reduced demand support for phthalic anhydride. Downstream industries maintained rigid demand procurement, and the phthalic anhydride market is expected to remain weak and consolidate in the later period.