The size of the moving window is a key parameter of for selecting wavelength variables, Therefore the MWRBFNN procedure had been carried out when the s the moving window was 5, 7, 9 and 11 for glucose and 21 of 31, 41 and 51 for pH values which were set due to the prelim inary experiments. The RBFNN models developed by raw spectra and each pretreated spectra were optimized by M WRBFNN and selected the most efficacious spect pre- treatment methods by using Da as criterion