On January 30, the market price of phthalic anhydride in East China showed a weak consolidation. The mainstream quotation for ortho-xylene-based phthalic anhydride was 6,000–6,300 yuan/ton, while the market price for naphthalene-based phthalic anhydride was 5,700–6,000 yuan/ton. The price of industrial naphthalene fluctuated and declined, while the price of ortho-xylene stabilized, leading to a decrease in the cost of phthalic anhydride. Downstream, the plasticizer market experienced fluctuating increases, with plasticizer manufacturers operating at low and stable equipment utilization rates. Downstream demand remained rigid, and purchases of phthalic anhydride were primarily based on immediate needs. Demand support for phthalic anhydride persisted, with manufacturers maintaining stable equipment utilization rates and sufficient supply. Phthalic anhydride inventory remained low. It is expected that the phthalic anhydride market will continue to consolidate weakly in the near future.