The volatile compounds of the essential oils of Carum roxburghianum Benth. (Radhuni) seeds of three different ecotypes of Bangladesh were obtained by hydrodistillation method and maximum yield was 2.57 % (w/w). The oils were analyzed by GC and GC-MS and thirty volatile compounds were identified and quantified. Predominantly monoterpene hydrocarbon accounted for 59.27-91.11 % of the total oil. The major constituents of the oils were limonene (29.33-59.37 %), 5,7,8-trimethyl-dihydrocoumarin (11.5326.69 %), sabinene (2.49-17.43 %), γ-terpinene (4.10-10.13 %), p-cymene (3.20-7.67 %), apoil (0.5-7.11 %), terpenolene (1.09-7.03 %), β-cis-caryophyllene (2.07-5.42 %), terpinene-4-ol (0.07-5.11 %), cis-sabinene hydrate (3.78-4.89 %), α-phellandrene (0.05-3.54%) and myristicine (0.28-2.33 %). The highest concentration of the elements (in ppm) were Ca 18900, Mg 6900, P 5500, K 5000, S 2900, Na 2000, Zn 115.0, Fe 105.0, B 43.0, Cr 0.561, Ni 0.464, Pb 0.042 and Co 0.033 in the three studied ecotypes. The Physico-chemical properties were evaluated. In the biological activities of the essential oils, the IC 50 value of the oils were 1147.12±6.99 μg/mL-1305.60±10.87 μg/mL at the highest concentration of 4000 μg/mL with 74.59±0.36 % inhibition by DPPH method. The LC 50 value was 2.17 μg/mL-2.53 μg/mL in the brine shrimp lethality cytotoxicity bioassay. The significant zone of inhibition was produced against some bacteria and fungi. These studies may find interest of several applications in pharmaceutical and food industries.