Objective: To understand and study the diagnostic criteria, treatment and prognosis of 2017 version of guideline for dementia with Lewy bodies (DLB) to elevate the understanding and recognition of DLB for having more patients to be diagnosed at early stage to receive whole-course management and comprehensive treatment. Methods: The clinical characteristics and treatment of 30 patients who met the 2005 version of diagnostic criteria for DLB were retrospectively analyzed and were diagnosed again using the 2017 version of diagnostic criteria for DLB. Results: According to the 2017 version of diagnostic criteria for DLB, 27 cases were diagnosed as probable DLB, 3 cases were diagnosed as possible DLB. There were 29 cases（96.7%） with Parkinson's syndrome, 16 cases（53.3%） with fluctuating cognitive impairment, 25 cases （83.3%） with visual hallucinations, 11 cases（36.7%） with REM sleep behavior disorder. There were 21 cases （70%） initiated with Parkinson's syndrome and 9 cases（30%）initiated with cognitive impairment and visual hallucinations. Conclusions: The 2017 version of diagnostic criteria for DLB increases the weight of REM sleep behavior disorder（polysomnographic abnormality） and abnormal ¹²³iodine-MIBG myocardial scintigraphy, providing objective basis for the early recognition and diagnosis of DLB, and is beneficial for patients to receive early management and comprehensive treatment, thereby improving the prognosis of the disease.