On February 2, the phthalic anhydride market in Shandong region experienced a weak consolidation. The mainstream negotiated prices for o-xylene-based phthalic anhydride were in the range of 6,000–6,200 yuan/ton, while naphthalene-based phthalic anhydride was quoted at 5,550–5,900 yuan/ton. The price of raw material o-xylene remained stable, while the price of industrial naphthalene declined, leading to a reduction in the production cost of phthalic anhydride. Downstream plasticizer prices fluctuated downward, and phthalic anhydride manufacturers maintained stable equipment operations. The operating rate of phthalic anhydride enterprises remained low but stable, resulting in a tightening of market supply. Plasticizer enterprises maintained steady production loads, but the rigid demand support for phthalic anhydride weakened. Looking ahead, the phthalic anhydride market is expected to continue its weak consolidation trend.