The spatial and temporal distribution of the oceanic boundary layer height is determined by wavelet covariance transform method using COSMIC and ERA-Interim refractive index data independently,then the difference between results of the two datasets is comparatively analyzed.The results show that a roughly same spatial pattern of not completely symmetrical distribution of the boundary layer height along the equator is observed for the inversion results of the two datasets.As for the seasonal and monthly variations,the oceanic boundary layer is relatively high in summer.Though no obvious diurnal variation is observed,it should be noted that the diurnal variation of boundary layer height from ERA-Interim data is more consistent with that of solar radiation.The comparison shows that the inversion results of COSMIC data are about 500-1 000 meters higher than those of ERA-Interim data,and the difference is greater in high latitudes than in low latitudes and smaller in summer than in winter.