In this diploma thesis, the possibility of optimizing the technological process of plant-based biostimulator production with the aim of increasing the process kinetic and yield of bioactive substances was investigated. Biostimulators were prepared by adding a mixture of selected dried plant material (comfrey root, nettle leaf, horsetail and marshmallow leaf) and tap water as solvent into the batch reactor. The optimization was performed using a single-variant "one time variable" technique, investigating the influence of the temperature, mixing, raw material/solvent ratio and aeration regime on the process kinetic and yield over time of 7 days. Values of 20, 25, 35 and 45 ° C were selected for the temperature, 250, 500 and 750 rpm for mixing, 15, 20, 25, 30 and 35 g L -1 for the raw material/solvent ratio, and for aeration the flow of air at 0.1; 0.3 and 0.5 L min -1 . After a set of experiments, it was determined that for this type of process the optimal parameter values are as follows: mixture temperature of 35 ° C, mixing speed of 250 rpm, raw material/solvent ratio of 30 g L -1 and aeration regime of 0.3 L min -1 . Also, the possibility of optimizing the reactor design for the extraction process was investigated, where it was shown that the design of the reactor with two perforated trays installed at 20% and 80% of the reactor height increases the process efficiency compared to the reference process. The process of plant-based biostimulator production at the Vedran Pezelj family farm in Trilj was used as a reference process, whose biostimulators have been on the market since 2018.