We calculate spectra of secondary particles produced in process of single
diffraction dissociation in the Model of Quark-Gluon Strings. For description
of diffractive dissociation process we use the reggeon model where all legs of
triple-reggeon diagrams are eikonalized. Numerical calculation shows that the
model gives a good description of data on charged particles pseudorapidity
distribution in ppˉ​ single diffractive dissociation