摘要Three cases of primary cold agglutinin syndrome were reported. Anemia aggravated after exposure to cold was the main clinical manifestation. Only case 2 suffered from acrocyanosis and Raynaud-like phenomena of hands and case 8 had hemoglobinuria. Case 2 had been misdiagnosed as paroxysmal nocturnal hemoglobinuria for 7years because of a positive Ham's test. Treatment with penicillamine and azathiopurine for IgM agglutinin in case 1 and treatment with prednisone for IgG agglutinin in case 2 provided effective symptomatic relief and reduction in antibody titers. In case 3 9-p-methylaniline acridine yielded some improvement. It is suggested that depending on the type of Ig different drugs should be used so as to get a better response. The mechanism of positive Ham's test in case 2 was also briefly discussed.