The main goal of this work was to study the impacts of humic acid (H) and Seaweed extract application (SW) on growth (plant height, number of branches/plant, fresh weight and dry weight of herb/plant) and (volatile oil %) and volatile oil content of Rosemary (Rosmarinus officinalis L.) plants were investigated during period from August 2024 to January 2025 in Misurata city, Libya.Four levels of humic acid including 0, 2, 4 and 6 ml/L in main plots. Four concentrations of Seaweed extract (SW) were assigned in sub-plots at 0, 100, 200 and 300 ppm as well as their interactions. The results demonstrated that the utilize of humic acid as well as Seaweed extract significantly improved the growth parameters, and oil extraction. Regarding this concern, the highest results were recorded through the addition of a high level of humic acid (6 ml/L) along with foliar spray of Seaweed extract (300 ppm) in comparison to the control during period growing. The volatile oil's GC-MS analysis revealed that the usage of biostimulant applications also had an impact on the main ingredients. In comparison to untreated plants, plants sprayed with 300 ppm of seaweed extract and a higher standard humic acid (6 ml/L) generally produced higher proportions of the principal components.