With paraffins and naphtenes raised from 35.1 to 78.5 vol.% in the feed, the extraction efficiency of all aromatics in onstep extn. at 50 degreesC fell by 7 wt.%, particularly that of toluene and C. aromatics (by 15 wt.%). The effect of solvent composition (N-methylpyrrolidinone-monoethylene glycol) in the range of 40-70 vol.% on the extn. yield was also studied. At 70 vol.% of the glycol, the extn. yield fell by 19.8% in comparison to that of 40 vol.%. With feed/solvent ratio changed from 1:3 to 1:4, the aromatics content in the extract raise by 3.6 wt.%.