By measuring the absorption and fluorescence spectra and the fluorescence lifetime of ^{4}F_{3/2} state of Nd^{3+} ions in YVO_{4} (2 at.-{\%}) crystal at different temperature, the effects of temperature on the spectra and the lifetime of ^{4}F_{3/2} state have been investigated. As the temperature is increased, the line width of the ^{4}F_{3/2}-->^4I_{11/2} transitions is found to increase and the spectral line toward the longer wavelength, which are duo to the ion-phonon interaction. The variation fluorescence lifetime of the ^{4}F_{3/2} state of Nd:YVO_{4} is found to be anomalous in the measured range 8-300 K. It is about 81 us at room temperature and decreases to 30 us at 8 K. The experimental results are explained by ascribing to the thermal mixing between the two Stark levels of ^{4}F_{3/2} state with different lifetime.