Objectitive The study was to evaluate the effectiveness of fluorescence-guided microsurgical resection of human glioma,and to investigate this technical tip and safety.Methods From Apil,2006 to October,2007,25 patients (13 women and 12 men;meanage 48.5 years old;agerange 15~66 years old) with human glioma underwent fluorescence-guided microsurgical resection by 5-aminolevulinic acid (5-ALA). The patients with glioma received 20 mg/kg 5-ALA before operation.The fluorescent regions of glioma were resected through a fluorescein surgical microscope after administration of fluorescer.To evaluate the effectiveness of the resection,operative findings were compared with histological findings from different fluore scent areas of these glioma.All patients were studied with MRI for detection of residual tumor.Results The rate of fluorescence positive was 96%, only one fluorescence negative case in all 25 cases.The viable tumor tissue was distinguished by its deep red fluorescence,whereas normal brain tissue was not stained.Our histological findings revealed a large number of tumor cells and a conspicuous vascular reaction such as proliferation of endothelial cells in the fl uorescein-positive area.On the other hand,the fluorescein-negative area showed only a small number of tumor cells and little vascular reaction.MRI after operation result demonstrated the completeness of tumor removal in these patients. Conclusion These results suggest that fluorescence-guided microsur gical technique by administrating 5-ALA may be practical and useful for the resection of human gliomas.By this method,surgeon can easily and rapidly gained objecti vestandard to judge the extent of removal in the operation.The technique may also be useful in indentifying tumour margins during surgery.Follow-up on patients who have undergone this surgery should be done to evaluate precisely effectiveness of this technique.