On June 9, the phthalic anhydride market in Shandong showed a weak consolidation trend. The mainstream negotiated price for o-xylene-based phthalic anhydride was 8,450–8,750 RMB/ton, while that for naphthalene-based phthalic anhydride was 7,600–7,900 RMB/ton. Crude oil prices declined from their highs, leading to reduced cost support. The price of raw material o-xylene fell, and industrial naphthalene prices also dropped, lowering the production cost of phthalic anhydride. The downstream plasticizer market displayed a strong consolidation pattern. Operating rates at phthalic anhydride plants remained stable, while overall capacity utilization in the phthalic anhydride sector showed weak consolidation. Supply in the phthalic anhydride market was ample. Plasticizer producers increased their operating rates, providing some rigid demand support for phthalic anhydride. The o-xylene-based phthalic anhydride market continued its weak consolidation trend.