Supercritical fluid chromatography (SFC) was considered for separating racemic ibuprofen. The chromatographic column (3.9 ${ imes}$ 150 mm) was packed with Kromasil$^{circledR}$ CHI-TBB, and the mobile phase was supercritical carbon dioxide with modifier of IPA. The experimental variables were the content of IPA, and temperature and pressure of supercritical mobile phase. To determine the separation condition, the empirical equation of retention factor and resolution was proposed. In the case of retention factor, the empirical equation was in the form, $k;=;a{ ho};+b/F;+;c;({ ho}/F);+;d$. The empirical equation for resolution was proposed as a linear form, $R;=;a{ ho};+;bF;+;c$.