On January 30, the phthalic anhydride market in Shandong region experienced a weak consolidation. The mainstream negotiated prices for ortho-xylene-based phthalic anhydride were 6,000–6,300 yuan/ton, while those for naphthalene-based phthalic anhydride were 5,700–6,000 yuan/ton. The price of raw material ortho-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 upward, and phthalic anhydride manufacturers maintained stable equipment operations. The operating rate of phthalic anhydride enterprises remained low but stable, resulting in a tightening supply in the market. The operating load of plasticizer enterprises remained steady for the time being, with continued support from rigid demand for phthalic anhydride. Looking ahead, the phthalic anhydride market is expected to continue its weak consolidation trend.