Abstract: The authors adopted a three-day pyronaridine-primaquine combination regimen in treating 656 patients (395 male, 261 female) with tertian malaria in 1976. The patients were divided into three groups. Group A: the total dosage of pyronaridine was 32mg/kg body weight (1.6g per adult), 0.8g for the first day and 0.4g for the second and the third day each; primaquine 30mg q.d. for three days. Group B: the total dosage of pyronaridine was 1.2g, 0.4g q.d. for three days; primaquine 30mg q.d. for three days. Control group: 126 patients treated with a total dosage of chloroqume 1.2g(0.6g for the 1st day, 0.3g for the 2nd and the 3rd day each) and primaquine 22.5mg q.d. for 8 days with a total dosage of 180mg. 100% immediate cure was observed in all the 3 groups and the relapse rate in groups A, B and C was 2.0%, 3.5% and 0.8%, respectively. On the whole, the three-day pyronaridine-primaquine regimen was found to have the following advantages: 1. rapid elimination of malaria parasites-48 hrs for the asexual and 72 hrs for the sexual forms; 2. rapid control of symptoms; 3. high rate of radical cure; 4. shorter term of treatment; 5. less dosage of primaquine.