A simple, rapid and precise microwave-assisted extraction process was developed and optimized for preparing n-hexane extract from shade dried seeds of Nigella sativa. This newly developed process was compared with conventional soxhlet extraction. The major parameters were studied and showed effect on extraction efficiency including processing time, strength of radiation, moisture content, mesh size and irradiated with and solvent free conditions. The most favourable condition was obtained by using plant material of coarse-powdered for 10 min at 340 W with nhexane solvent under moisture. Observation was suggested that no change in composition of constituents of both extracts;under microwave and conventional soxhlet extraction which examined by TLC. The extraction rate observed first order kinetics under microwave radiation. Anew compound was isolated and identified as dotriaconta-2, 9, 25-triene from unsaponifiable matter of n-hexane extract of seeds on basis of spectral and literature studies.