Abstract: Comprehensive analyses were done of the near-surface flow field and low-level wind and temperature observations made on the western outskirts of Haikou,Hainan Island.The characteristics of the near-surface flow field, the observational cases and behaviour patterns of coastal low-level land-sea breezes with respect to the generation and development were discussed.It was found that the land-sea breezes occur at a frequency of 75% and in the daytime the sea breezes lasts for 1-4 hours normally and for 10 hours in the extreme case.