Using auroral observations at Zhongshan Station, Antarctica with a multi-channels scanning photometer, and Interplanetary Magnetic Field (IMF) and solar wind parameters observed by Wind Satellite at the upstream of the bow shock in 1997 and 1998, the dependences of the highlatitude postnoon auroral intensity upon solar wind-magnetosphere coupling functions are studied quantificationally. It shows that the intensity of the postnoon 630 nm emission is highly dependent on the solar wind electric field and the solar wind energy density flux, the postnoon auroral emission has larger correlation coefficients with the solar wind electric field functions than with the solar wind energy density flux functions, which is consistent with Liou's result derived from images acquired by the ultraviolet imager on board Polar satellite. The dependences of 630 nm emission on the different solar wind electric field functions related to the clock angle are varied, which implies that the clock angle of the interplanetary field is also a very important factor on postnoon aurora. The dependencesof the postnoon auroral emission on solar wind-magnetosphere coupling functions and trans-polar potential functions are also studied. The intensity of the 630 nm emission depends on these functions more directly than that of the 557.7 nm emission.