In this work, we searched for short-timescale variations of polarizations in five magnetars observed by the Imaging X-ray Polarimetry Explorer. Only 4U 0142+61 showed an indication of variations of polarization degree (PD), with the significance of 3.0σ between the highest and lowest PDs, though no significant changes were observed in the polarization angle and emission features during this process. 1RXS J170849.0−40091, SGR 1806−20, 1E 2259+586 and 1E 1841−045 remained stable within the error ranges. To verify these results, we also performed simulations assuming constant polarization over their observation period. The results indicated that the probability of the detected PD of 4U 0142+61, being due to statistical fluctuations is only 5.8%. However, we cannot rule out the possibility of statistical fluctuations for 4U 0142+61, if the observed PD variation is indeed a real physical phenomenon, which would be necessary to be confirmed in future observations.