Research on reliable ungulate population size estimation has always been a core and confusing problem in north China. Currently, four methods are widely used in ungulate population size survey in north China, i.e., transect method, belt transect method, sample plot and non-invasive CMR method. However, these four methods are based on different assumptions and calculating methods, which may lead to significant differences in results generated by different methods. It is an urgent need to make a validity evaluation for the effectiveness of the four methods. We used the four methods mentioned above to assess the population size of moose (Alces alces cameloides) in an area of about 120km² in Hanma National Nature Reserve in two time frame, Feb. to Mar. 2012 and Dec. 2012. Theresults showed that population size estimated by these methods were 168 (109-227) individuals, 237 (165-309) individuals, 37 (23-50) individuals, 55 (43-68) individuals, correspondingly. It is obvious that results from the two methods (transect method and belt transect method) traditionally used in north China are significantly higher than those of the two methods (sample plot and non-invasive CMR method) newly introduced to China. We further discuss the reliability, limitation and applicability of different methods to provide scientific reference to selection and application of suitable ungulate population survey methods during winter in north China.