The work is a continuation of studies to determine the impact of moisture content and chamber parameters on densification of biological raw materials. The paper presents the results of investigations conducted to determine the impact of giant miscanthus compaction conditions on the parameters of the process and the strength of the agglomerate. The experiments were performed with the help of a universal strength tester, ZWICK Z020/TN25, and a closed compression assembly (die) with three chamber diameters of 12 mm, 15 mm and 18 mm. The relationship between the density of the material in the chamber and the agglomerate, the degree of compaction of the agglomerate, work effort on the compaction, coefficient of susceptibility of the material to compaction and the agglomerate mechanical strength and moisture content of giant miscanthus for the three diameters of the chamber were determined. It was found that the densification parameters depend in varying degrees on the moisture content of giant miscanthus and on the die chamber diameter. Increase in moisture content improves the susceptibility of material to agglomeration and worsens the quality of the agglomerates in terms of their strength.