Some results are presented concerning investigations in laser desorption of neutral organic molecules by various laser wavelength into a supersonic jet followed by either single or multiphoton ionization. The results demonstrate that resonant absorption of photons in the desorbing materials must take place in order to observe high quality mass spectra. Non resonant laser desorption requires significantly higher laser powers than the resonant desorption. It is shown that in case of smaller biomolecules multiphoton ionization is superior to single photon ionization with 118 nm photons. Some applications of the multiphoton ionization on small protected nucleotides are shown and disscussed.