The direct effect of lower-tropospheric diabatic heating (DH) on surface circulation over the equatorial Pacific is revealed using the theoretical analysis and three atmospheric general circulation model (AGCM) simulations, only differing their moist processes. The AGCM results suggest that the insensitivity of surface wind to DH in the middle and high levels is closely associated with the vertical disagreement of DH between the layers below and above 925 hPa over the equatorial Pacific.