Objective To understand the causes of misdiagnosion and study the methods of diagnosis for Cryptococcus neoformansis meningitis.Methods Cerebrospinal fluid (CSF) was stained by black ink, then them were detected with microscope to look for Cryptococcus neoformans.Results 13 patients with Cryptococcus neoformansis meningitis were all detected Cryptococcus neoformans in CSF. The control cases were all negative results to apply the same method.Conclusion The causes of misdiagnosis for Cryptococcus neoformansis meningitis are very much alike both Cryptococcus neoformansis meningitis and tuberculosis meningitis, and the method do not apply in routine CSF test for CSF be stained by black ink. It is a very much useful method on CSF is stained by black ink for detection of Cryptococcus neoformans. The method ought to apply in routine CSF test.