A novel series of histone deacetylase inhibitors combining N-hydroxycinnamamide bioactive fragment and indole bioactive fragment was designed and synthesized. Several compounds (17c, 17g, 17h, 17j, and 17k) exhibited comparable, even superior, total HDACs inhibitory activity and in vitro antiproliferative activities relative to the approved drug SAHA. A representative compound 17a with moderate HDACs inhibition was progressed to isoform ...