Determination of the number of J/$\psi$ events with J/$\psi$ \rightarrow decays

The number of $J\mathrm{/}\psi$ events collected with the BESIII detector at the BEPCII from June 12 to July 28, 2009 is determined to be $(225.3\pm 2.8)\times {10}^6$ using $J\mathrm{/}\psi \to inclusive$ events, where the uncertainty is the systematic error and the statistical one is negligible.