The forced vertical oscillations of a single dust particle trapped in a standing striation are investigated. The particle oscillations associated with the displacement of the striation are induced by square wave modulation of discharge current. Amplitude frequency characteristics depending on the shapes of modulating signal are measured at pressure p = 0.16 torr. The resonance frequency, the eigenfrequency, the damping constant, and the amplitude of the resonance peak are determined. The quantitative description of the resonance behaviour of the dust particle is based on the theory of the forced harmonic oscillator. The Q-factor of a dusty plasma system is measured for the first time. The Q-factor takes the value of the order of several units, which indicates the large energy dissipation in the dusty plasma systems.