Current study focused on two phases; in the first the composition and the amount of extractives were determined. Thus, hexane and acetone:water (95:5, v:v) extracts of Eucalyptus camaldulensis and Liquidamber orientalis bark were analysed by GC-MS to determine lipophilic and hydrophilic extractive composition of these species. The second phase was to identify anti-bacterial, anti-biofilm and anti-swarming effects of the gathered extractives. Total amount of lipophilic extractives was found 3.90 mg/g in E. camaldulensis whereas it was determined as 7.67 mg/g in L. orientalis bark. However, total amount of hydrophilic extractives in E. camaldulensis bark (55.51 mg/g) had almost 1.5 times more than L. orientalis bark (39.19 mg/g). Fatty acids and sugar groups were the dominant groups as lipophilic and hydrophilic, respectively, in both species. Anti-bacterial test was carried out by using three Gram-positive (Staphylococcus aureus, Methicillin Resistant Staphylococcus aureus, Bacillus cereus) and three Gram-negative (Pseudomonas aeruginosa, Escherichia coli and Pseudomonas aeruginosa PA01) strains with agar well diffusion method. In addition, the minimum inhibitory concentrations (MICs) of the extracts were also determined using the micro-dilution method. When hexane and acetone:water (95:5, v:v) extracts of E. camaldulensis and the acetone:water (95:5, v:v) extract of L. orientalis have anti-bacterial effect on Gram-positive bacteria but they do not have anti-bacterial effect on the tested Gram-negative bacteria. Whereas the hexane extract of L. orientalis did not show anti-bacterial activity on any tested strains. The minimum inhibitory concentration of these extracts ranged from 0.52 to 51.5 mg/ml. It was also found that hexane extract of E. camaldulensis inhibited biofilm formation and acetone extract of L. orientalis and E. camaldulensis indicated anti-swarming activity on P. aeruginosa PA01.