Abstract： Objective:To evaluate the therapeutic effect of hemopurification on acute chlorfenapyr poisoning according to the blood concentration of chlorfenapyr and to provide experience for clinical treatment.Methods:Two patients who presented to our Emergency Department following an ingestion of chlorfenapyr and then were treated with hemopurification in 2022 were included. The concentrations of chlorfenapyr and its highly toxic metabolite tralopyril were dynamically monitored, and the clinical data of the patients were collected.Results:Case 1 was given hemoperfusion for the first time 13 hours after ingestion. During l hour hemoperfusion, the tralopyril decreased by 28.82%. The concentration increased and exceeded the pre-perfusion level after 2 hours of hemoperfusion. After three times of hemoperfusion, the concentrations of chlorfenapyr and tralopyril were still higher than those before the first time, reaching 248 ng/mL and 1 307 ng/mL respectively. The concentration of chlorfenapyr showed a downward trend after 130 h, and the tralopyril in blood reached the peak 3 164 ng/mL at 130 h and decreased to 2 707 ng/mL at 178 h. In case 2, the blood chlorfenapyr and tralopyril concentration was 392 ng/mL and 7 598 ng/mL respectively 150 hours after ingestion. The blood chlorfenapyr concentration decreased by 37.75% respectively after first hemoperfusion, and the tralopyril concentration decreased by 38.02% respectively. During 85 hours of continuous veno-venous hemodiafiltration (CVVHDF), the concentration of tralopyril was maintained at 4 234~6 410 ng/mL. Case 1 was followed up to 12 days and lost follow-up. Case 2 died and the survival time was 247 hours.Conclusions:Hemoperfusion can scavenge tralopyril, but CVVHDF has poor scavenging ability for tralopyril. And the apparent volume of distribution (Vd) of chlorfenapyr and tralopyril are large. After ingestion, chlorfenapyr spreads to various tissues quickly, and it is easy to accumulate in the adipose tissue. The chlorfenapyr in the tissue slowly is released back to the blood and stays in the blood for a long time. The peak concentration of chlorfenapyr appeared earlier than that of tralopyril. Clinicians should pay attention to the early removal of toxins from the digestive tract.