Abstract: We give two models of VMF1 and GMF derived from ECMWF data based on NMF model,present the space-time analysis of three mapping functions.A real example of ground-based GNSS retrieved water-vapor is given to demonstrate the accuracy of VMF1 and GMF models.It is shown that the application of VMF1 and GMF improves the precision of GNSS retrieved water-vapor.At the same time,many investigations may be concentrated on the repeat rate of baseline length,absolute changes of station heights,and the terrestrial reference frame.