We have studied the electronic state of Fe atoms in SrFe2As2 under pressure at room temperature by 57Fe Mossbauer spectroscopy using a single crystalline sample. A center shift δc.s. and an electric quadrupole interaction parameter e2qQ/2 show the discontinuous increase and decrease at around 7 GPa,respectively, implying the pressure-induced structural phase transition. Furthermore, δc.s. deviates from the linear pressure dependence above 4 GPa without any anomaly in the pressure dependence of e2qQ/2. The anomaly corresponds to a change of the pressure dependence of lattice parameter ratio c/a, where volume of the unit cell decreases monotonously with increasing pressure.