Black cumin seed (Nigella sativa) oil was used traditionally in different countries for manyrnmedical complains. The seeds are used for culinary purposes, medicinal treatment and alsornused as food additives. The oil can produce by different extraction methods. Among of thosernmethods, solvent extraction is the most promising and effective process with minimum cost.rnWhen we are using solvent extraction process, the major problem is the uses of toxicrnchemical that is hexane as a solvent. These solvent produces photochemical oxidants in thernozone by reacting with other pollutants during extraction and recovery process and also arntrace of hexane that is found in the oil affects the human health. This study mainlyrninvestigates and compares the effect of solvents, ethanol and hexane in the extraction processrnand optimization was done in the two factors named as, extraction time and seed to solventrnratio. The extraction process was carried out by using 3 level factor of the seed to solventrnratio (1:4, 1:6 and 1:8) and 4 level of extraction time (2hr, 4hr, 6hr and 8hr) using for eachrnsolvents using soxhlet extractor. The maximum yield of extraction for hexane solvent wasrnfound to be 35.725% with seed solvent ratio 1:8 and 4 hour and the minimum yield werern20.575% with the seed solvent ratio 1:4 and 2 hour of extraction time. Whereas using ethanolrnsolvent the higher extraction yield was 35.51% with the factor of the 1:6 of seed solvent ratiornand with extraction time 6 hour and the minimum result were 22.81%withthe seed solventrnratio 1:4 and 2 hours. The significance of each parameter was checked by using designrnexpert software with the p-value