The variations of the first-order Schumann resonance frequency in Kola peninsula are studied for four solar proton events on November 4 and 6, 1997 and on May 2 and May 6, 1998. It is found that the frequency decreases by about 0.15 Hz during the peaks of the proton penetrations. Such a decrease is in agreement with modeling calculations. A very intensive solar X ray burst preceding the proton flare on November 6 caused an increase of the resonance frequency. The decrease of amplitude about of 0.2 pT and the decrease of the resonance bandwidth about of 0.2 Hz are observed in the November events.