Abstract: For surface flux measurements, large aperture scintillometer (LAS) has become more and more popular in recent years. Compared with traditional observation techniques, it can measure surface fluxes on a larger scale (500 m-10 km). At present, LAS observation is not common in China. Beijing Normal University, associated with other institutes, has carried out several short term measurements of LAS at Xiao tangshan (Beijing, 2002, 2004). A long-term LAS site has also been constructed at Miyun (Beijing) in June, 2006. Sensible heat flux (H) calculation with the LAS data of above measurements shows that the beam height of LAS and wind speed are sensitive factors for sensible heat flux measurement (H_LAs), zeroplane displacement height is crucial unless the beam height is much lager than it, and Bowen ratio needs to be determined accurately over wet surface, while air temperature, air pressure and aerodynamic roughness length are not sensitive for H_LAs. There are two key points of H_LAS calculation under stable condition. First, there is much less agreement on the form which universal stability function f_T should take. In this study, the f_T function proposed by Andreas (as in the LAS manual) is used. Further more, since the iteration process of H_LAS can not be convergence when low wind speed and very stable conditions appearing at night, ψ_m≥-5 is specified. Second, the scintillometer is unable to determine the sign of the heat flux. Richardson Number R_i can be used to determine atmospheric stability and fix the sign of H_LAS. Besides, the sunrise-sunset time and net radiation could be used for this purpose if there is no wind and air temperature profiles. Therefore, a calculation scheme of 24-hour sensible heat flux observed by LAS is obtained after settling the above two key points. According to the observations mentioned above, LAS can measure surface fluxes both over homogeneous and heterogeneous surfaces. The daily and monthly variation of H_LAs is analyzed. And the observation differences between eddy covariance system and LAS, need to be studied further combined with footprint model and energy unbalance of eddy covariance system observation.