Abstract: The purpose of this article is to investigate the moderation characteristic ofzirconium hydride in the multiplication assembly. Seven critical experiments wereperformed with the N_H/N_5 ratio ranging from 233 to 543. On the twoquasi--homogeneous lattices, which have N_H/N5 ratio 233 and 337, series ofexperiments have been accomplished. Part of the experimental results werecompared with the theoretical calculation, The agreement between them indicatesthat the theoretical model used in calculation is applicable.