Soybean oil (SBO) was carried out deodorization at 4 factors as controlled maximum deodorizing temperature (DT), vacuum degree (VD), cycle time (CT) and treating amount of stripping steam (TASS). The results were as follows, acid value (AV), peroxide value (PV) and trans fatty acid content (TFAC) in produced deodorized SBO. Obtained deodorized SBO at high DT had the lower AV, PV, but TFAC was increased relatively. A suitable level of VD and TASS was 4.0 torr and 2.0%(w/w), than the longer CT was appeared a superior quality level. As a result, the best deodorizing conditions in SBO for lower TFAC were maximum DT; $235^{circ}C$, VD;4.0torr, CT; $14{sim}15min$ and TASS; 2.0% (w/w). Deodorizing conditions for lower TFAC in deodorizing of SBO was the major factor, more than lower DT was difficult because of the others quality factors.