This study was carried out to investigate aroma patterns of Hanwoo (Korean cattle) beef by using anElectronic nose. The M. longissimus muscle and Semimembranosus muscle after 24 hours postmortem wasobtained, and half muscles cooked in water batch until internal temperature arrived at 70℃ or microwavefor 30 sec. The raw and cooked beef samples stored at 1℃ for 11 days. Sensitivity values (dR/RO) amongelectronic nose data were changed differently by muscle parts, heat treatments and storage days. ThedR/RO values from SY/LG, T30/1, P10/1, P10/2 were decreased at 11th storage compared with those at1th storage. Mapping these data by using PCA (principal component analysis) showed that raw and cookedbeef data were presented on the right and left side of board, respectively. The data of 1st storage werepresented on the right side, and flock together. Otherwise, the data of 11th storage were spreaded out morewidely on the left side. Consequently, the dR/RO value and PCA mapping by Electronic nose data showeddifference by sample treatments and storage days. Therefore it will be possible to able to detect separatedaroma patterns of Hanwoo beef by using an Electronic nose.