On January 28, the DBP market in Jiangsu region saw an increase, with quotations at 7,900 yuan/ton. The DBP market in Shandong region also rose, with quotations at 7,800 yuan/ton, while the DBP market in Zhejiang region increased, with quotations at 8,000 yuan/ton. On January 28, the price of n-butanol, a raw material for the plasticizer DBP, fluctuated and rose. The price of phthalic anhydride fluctuated and stabilized, and the price of isooctanol fluctuated and increased. The cost of DBP raw materials rose, while PVC prices fluctuated and stabilized. Downstream demand remained weak, and DBP production equipment experienced a slight decline in operating rates. DBP supply was sufficient, and DBP factory inventories were low. Downstream customers showed moderate purchasing enthusiasm, with transaction prices determined through negotiation. DBP prices ranged from 7,800 to 8,000 yuan/ton. DBP prices increased, with downward pressure weakening and upward momentum strengthening, leading to a rise in the DBP market.