Objective To detect the content of free DNA and the DNA integrity in serum and cerebrospinal fluid (CSF) from glioma patients in order to assess their diagnostic value for the glioma.Methods Serum samples were obtained from 70 patients with glioma and 22 healthy volunteers as controls,and CSF samples from 20 patients with glioma and 8 nonneoplastic controls with hydrocephalus or arachnoid cyst.Free DNA concentration and integrity were detected by using real-time quantitative polymerase chain reaction (RT-qPCR) before operation.With 2 primers sets amplifying short and long free DNA fragments ( ALU115 and ALU247 ),free DNA integrity was determined by ratio of the concentration of ALU247 over ALU115 (ALU 247/115).Results The concentration of serum ALU had no significant differences between glioma patients and healthy controls.ALU115 and ALU247 contents,and free DNA integrity in CSF were significantly higher in glioma patients than in the controls ( all P<0.05 ).Area under curve of ROC curve analysis for the CSF free DNA integrity,and content of ALU115 and ALU247 for the diangosis of glioma was 0.912,0.775 and 0.875,respectively.Conclusion The CSF free DNA concentration and integrity may serve as a new marker for the diagnosis of glioma. Key words: Glioma; Free DNA; Serum; Cerebrospinal fluid; Diagnosis