A laser tweezers Raman spectroscopy (LTRS) system was used to investigate the capacity of carrying oxygen in thalassemia erythrocytes. Single erythrocyte from patients with thalassemia HbH-CS and normal donors were trapped,and the Raman scattering signal of trapped cell was collected. The intensity ratio of band 1638 cm-1 to band 1547 cm-1 (I1638/I1547) was selected to distinguish oxygenated erythrocytes from deoxygenated ones. By comparing the oxygenation cycle of optically trapped single red blood cells and the deoxygenated cells population from the two kinds of specimen,and analyzing the oxygenated and deoxygenated states,it is found that,in the oxygenation cycle,the ratio I1638/I1547 of thalassemia HbH-CS was much higher than that of normal control in deoxygenated state and slightly higher than the normal control in oxygenated state. In the population statistic,46% of the red blood cells from the normal control reach oxygenated state,but thalassemia HbH-CS only 15%,if the base is set by less than the average of I1638/I1547 from normal control cells. The result shows that the red blood cells of thalassemia HbH-CS are easy to oxygenate,but difficult to deoxygenate. The individual difference between thalassemia HbH-CS erythrocytes is obvious. This study provides the spectral vision on the oxygenation of thalassemia HbH-CS erythrocytes and the laboratorial referrences for the diagnosis and treatment.