The invention provides an [alpha],[beta] unsaturated amide compound having anticancer activity shown by formula (I) or a pharmaceutically acceptable salt or the like thereof: [in the formula, A represents an optionally substituted heterocyclic diyl, R1 represents a hydrogen atom or an optionally substituted lower alkyl, R2 represents an optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted aliphatic heterocyclic group, or optionally substituted aromatic heterocyclic group, X represents -O-, -S-, -SO2-,-NRX1- (in the formula, RX1 represents a hydrogen atom or a lower alkyl), CHRX2- (in the formula, RX2 represents a hydrogen atom or a hydroxy), -CH=CH-, -CO-, or -NH-CO, n1 and n2 are the same or different and each represent 0 or 1].本發明提供下述式(I)表示之具有抗癌活性等的α、β不飽和醯胺化合物或其藥學上容許之鹽等：[式中，A表示可具有取代基之雜環二基，R1表示氫原子或可具有取代基之低級烷基，R2表示可具有取代基之芳基、可具有取代基之環烷基、可具有取代基之脂肪族雜環基或可具有取代基之芳香族雜環基，X表示-O-、-S-、-SO2-、-NRX1-(式中，RX1表示氫原子或低級烷基)、-CHRX2-(式中，RX2表示氫原子或羥基)、-CH=CH-、-CO-或-NH-CO-，n1及n2，係相同或相異地，分別表示0或1]。
