Spectral and photophysical properties of a number of amino- and hydroxycoumarins have been studied experimentally and theoretically using the methods of quantum chemistry. The probability of different pathways of the photoprocesses is shown to be dependent on substituents and a position and a nature of molecular orbitals. It is shown that fluorination most strongly influences the properties of the pp* excited states because of unique electronic effect of fluorine atoms and due to significant charge transfer at these excited electronic states.