In this thesis, the quantitative analysis of intact proteins using ion mobility spectrometry was introduced for the first time. Also, Pneumatically assisted electrospray (Ion Spray) ionization source for using in the ion mobility spectrometer was designed and Constructed. In the proteomics studies, after recognition of proteins, measurement of their concentration is of great importance. There are two significant methods for quantitative analyses of proteins. One of them, intact protein analysis (without their transformation into peptides) and the other is digestion of proteins to their peptide composers followed by their measurement. In this thesis, the first method was used for quantitative analyses of insulin protein with relatively low molecular weight (about 6000 Dalton) and albumin protein as bovin serum albumin and human serum albumin with high molecular weight (about 67000 Dalton). Mobile phase flow rate and nebulizing gas flow rate parameters were optimized in order to achieve the highest response (sensitivity). In the analysis of each one of these proteins, a mixture of water and methanol (1:1) was used as solvent and mobile phase. Then pH of each one of these solutions was decreased about 1 unit below the isoelectric pH of proteins using acetic acid, not only for better solubility, but also for having capability of analysis in the positive mode of ion mobility spectrometer. Initially, insulin was considered. Ion mobility spectrum was compared with electrospray and ion spray ionization source, and results clearly showed the effect of nebulizing gas in the ion spray on the signal intensities. This significant increase is due to formation of very small aerosols of big clusters from proteins together with solvent in the presence of nitrogen nebulizing gas. Existing of multiply charged states was demonstrated by comparison of two-dimensional mass and ion mobility spectra reported in the papers. The values of reduced mobility resulting from insulin verifies the presence of +3, +4 and +5 states, that it is because of protonable amino acids in insulin protein. Then quantitative analysis of insulin was performed under optimized ion spray condition. In each case, ion mobility spectra was recorded from its appearance to obscurity. Then with using Matlab software, averaging the spectra was performed, background correction was carried out and the integral of area below the peak was recorded as instrument response. In the case of insulin, linear range was 0.2-13 ?M and detection limit was 0.05 ?M. Two additional proteins were analyzed similarly. The influence of nebulizer gas in these two proteins which their molecular weights are higher than insulin was more clearly. The linear range of bovin serum albumin was 0.075-1.5 ?M and its detection limit was 0.02 ?M, and in the case of human serum albumin, linear range was 0.03-1.5 ?M and detection limit was 0.009 ?M. Considering these represented results, it is expected that this protein analysis method with advantages such as simplicity, fast response, suitable detection limit and linear dynamic rang be used for quantitative analysis of biomarker proteins in biological fluids.