We behavior of a three-dimensional hydrogen atom in a strong linearly polar
ized laser field of femtosecond duration is examined by direct numerical in
tegration of the time-dependent Schrodinger equation. Analysis is performed
for a broad range of parameters of laser pulses and different initial atom
ic states [nlm] Our investigations reveal various mechanisms behind ionizat
ion suppression, which may replace each other, depending on the laser inten
sity. Conditions of stabilization of different types are studied.