We have monitored the blazar 3C 454.3 since 2008. The object was reported to be bright in the near-infrared and gamma-ray bands (ATel #2988 and #2995). We also confirmed this flare. Figure shows the light curve and the temporal variation of the polarization degree in the V band. The amplitude of the magnitude was about 1.1 mag from JD 2455496 to 2455502. The polarization degree in JD 2455502 was about 34 %, and was higher than that in the 2009 flare during Dec. 2009 (around JD 2455180).