Abstract: In 2020, the same equipment and the same laser parameters of sodium fluorescence lidar were used to simultaneously observe the sodium layer over different latitudes. This paper systematically explores the monthly characteristics of the overall sodium layer in two regions in 2020 through the sodium layer echo photon data obtained from the observation, and inverts and analyses the raw data to reveal the geographic differences of the sodium layer at different latitudes. It is found that except August, the average monthly column abundance in Beijing (40.5°N, 116.0°E) at mid-latitude is higher than that in Haikou (20.0°N, 110.3°E) at low latitude. According to the statistics of special events in 2020, the probability of Sporadic Sodium Layer (SSL) events in Beijing and Haikou is 5.3% and 44.9% respectively, and the probability of Double Sodium Layer (DSL) events is 5.3% and 4.3% respectively; the peak altitude of SSL events in Beijing is located at a higher height throughout the year, and strength factor of SSL reaches the maximum value of 10.6 throughout the year. By comparing the ionosphere data by an ionosonde operated at Danzhou, China (19.5°N, 109.1°E), it is found that SSL events above 96.0 km in Haikou have a high correlation with Sporadic E layer (Es). Monthly average peak value of the SSL events in Haikou is higher than that in Beijing, and the peak altitude is the opposite. Comparison between two regions shows that without excluding the special events, the monthly trend of sodium layer in Beijing is more regular than that in Haikou. SSL events in Haikou are more frequent, DSL events are more concentrated in Beijing, and they are extremely frequent in May, which may be the result of the modulation of Es and other factors. The average peak altitude of the secondary sodium layer of DSL events in both regions are located near 110 km. This work can further refine our understanding of the behavioral characteristics of sodium layers, providing reference data and conclusions for future research on sodium layers.