The article presents an innovative mixing-densifying-dosing system of a pelletizer, which feeds plant material to the densifying system. The structure of the system allows simultaneous realization of the mixing operation as well as non-pressure compression of powdery fractions of the processed material. The paper also sets forth results of the presented system. The tests included determination of the rotational speed of the internal cylinder of the system (25, 40, 55 rot·min-1) and mass intensification of the densified raw material flow (4, 8 and 12 kg·h -1) on the amount of the pelletized fraction. Fine-grained waste of nettle from Herbapol plants in Białystok was used as a research material. The tests which were carried out allowed determination of the mixing-densifying -dosing system for initial densification of the fine-grained plant material (nettle waste) before feeding it to the working system of the pelletizer and allowing elimination of the finest fractions of the crumbled plant material by its non-pressure compression during mixing.