Abstract: In order to measure Hainan tourism spatial agglomeration, yearly statistical data and spatial relationships between tourism spots, starred hotels and travel agencies of Hainan island were analyzed by utilizing Hefindahl index, Location Quotient, Nearest Neighbor Index, Spatial Connection Index and Geographic Concentration Index. The following conclusions were reached: regional and cities' agglomeration was obvious; the overall agglomeration was increasing as time flows and it's more agglomerated than the average of primary, secondary and tertiary industries; the eastern part was the most clustered, northern part and southern part were two tourism spatial agglomeration areas. The influencing factors of Hainan tourism spatial agglomeration were tourism resource endowment, industry characteristics, geographic conditions, governmental policies and the overall economic development level. Different spatialscale regions and differentcharacteristic scenic spots were dominated by different influencing factors. Largescale regions such as Sanya and Haikou were influenced by the location and governmental policies. Mediumscale counties' tourism mainly depended on tourism resource endowment. Smallscale scenic spots had comparably complicated dominating factors but were mainly concerned with its characteristics.