Time of flight mass spectrometry is one of the most sensitive and widely used methods for material analysis. In TOF-MS molecules are ionized, accelerated and separated in a field free region. In fact, ions of different m/z are dispersed in time during their flight along a field free drift path of known length. The lighter ones will arrive earlier at the detector than the heavier ones. In this work the TOF-MS, constructed in Laser Laboratory of Isfahan University of Technology was used to record mass spectra of amino acids, including; phenylalanine, alanine, valine and proline. An Nd:YAG laser at first harmonic (1064 nm) was used as a desorption/ionization source. The new method, introduced in the laser laboratory of chemistry department of Isfahan University of Technology, was used. In this method, laser is irradiated on the backside of a plate on which amino acid and an alkali salt is coated. Because of no direct interaction between the laser light and sample, little or no fragmentation was observed. Laser energy on the backside of the plate causes the amino acid and alkali salt to evaporate and the alkali cation is attached to the amino acid molecules. In this work, firstly the mass spectrum of the blank plate (Stainless Steel 0.1 mm thick) was recorded. Ions of K + , Cr + , Mn + and Fe + were observed and used for mass calibration. In addition, mass spectra of NaF and LiCl on the plate were separately recorded and ions of Na + , Na + (NaF), Li + and Li + (LiCl) were observed. Finally, phenylalanine and sodium fluoride were loaded on the plate and mass spectrum was recorded in which [M-H+2Na] + was observed. The experiment was tried with lithium chloride and better results were obtained. It was concluded that lithium attaches better than sodium cation to amino acids. Hence, the mass spectra of phenylalanine, alanine, valine and proline with lithium chloride were recorded. Similar ions as to MALDI like [Amino Acid+2Li-H] + were observed for all aminoacids.