Conjugated linoleic acid-rich cotton seed oil is produced via one-step Ru-catalyzed isomerization. Ru black enables 51.32% conversion of linoleic acid & 83.70% selectivity. Linoleic acid in Sn-2/Sn-1,3 positions doesnot show significant difference for isomerization. XPS deconvolution reveals a correlation of Ru content vs catalytic property. Reaction activity/selectivity shows a pronounced correlation to Ru(IV) content.