A polarizing plate is provided and is excellent in characteristics of optical compensation, small in a change of polarization performance over time and excellent in moisture and heat resistance. The polarizing plate contains a polarizing film and two transparent protective films provided one on each side of the polarizing film, in which at least one of the two protective films is an optical compensatory sheet containing a cellulose acylate film. The polarizing plate has specified single-plate transmittance and polarization degree P and has specified ranges of variations of the transmittance and the polarization degree P after a passage of a specified period of time under a high-temperature high-humidity atmosphere and a high-temperature low-humidity atmosphere. The liquid crystal display device of VA mode using the polarizing plate is provided.