No. 87 (00208) Family name : Bityukov Given name : Sergei I. Affiliation : Institute for high energy physics Abbreviation : IHEP E-mail address : Serguei.Bitioukov@cern.ch Title : Experimental test of the probability density function of true value of Poisson distribution parameter for observed number of events Authors : S.I. Bityukov, V.A. Medvedev, V.V. Smirnova (IHEP, Protvino) Abstract : The probability density function of true value of Poisson distribution parameter for observed number of events is constructed by computer experiment. The analysis of the PDF confirms that this distribution is gamma-distribution.