This letter definitely evaluates inner pressures of microbubbles in liquid argon and water by molecular dynamics simulation. The microbubbles are modeled with spherical cavity, which circumvents most uncertainties about microscopic definition of curved surface and related quantities. In both liquids, the inner pressure deviates downward from the Young-Laplace equation when the cavity radius is smaller than two molecular diameters, and takes a maximum, about 900 and 3000 atm, respectively, at the cavity radius being similar to 3 angstrom. The hydrogen-bonding character of water plays little specific role in the deviation of the inner pressure. (C) 2013 Elsevier B.V. All rights reserved.