Abstract: Objective: To study the relationship of paraneoplastic neurological syndromes(PNS) with malignant tumors and clinical types.Methods: Immunohistochemistry(ABC method) and Western blot analysis were used to detect specific neuronal antibodies in 430 PNS patients with malignant tumors.Results: Clinical types of 430 PNS patients include paraneoplastic sensory neuronopathy,paraneoplastic encephalomyelitis,paraneoplastic cerebellar degeneration,paraneoplastic limbic encephalitis and paraneoplastic opsoclonus myoclonus,PNS may complicate any malignant tumor but is more common with small cell lung cancer,breast cancer,ovarian cancer and Hodgkin's lymphoma.The high titer specific neuronal antibodies have been confirmed in the serum and cerebrospinal fluid of 281 patients.Conclusions: Various specific neuronal antibodies found in PNS patients strongly demonstrate that PNS is autoimmune disorders of nervous system resulting from malignant tumor,and detection of these specific neuronal antibodies is favorable for early diagnoses of PNS and associated malignant tumors.