Epithelial ovarian cancer (EOC) is highly metastatic and current therapeutics are unsatisfactory. Cancer stem/stem-like cells (CSCs/CSCLs) represent a rare population of undifferentiated oncogenic cells responsible for tumor initiation and maintenance. We identified ovarian cancer ALDH(high) (aldehyde dehydrogenase) population could perform not only strengthened CSCLs properties embodied in colony formation, CSCs-markers expression, and tumorigenesis in vivo, but also a greater invasive capacity with advanced EMT progress and anti-apoptosis compared with ALDH(low) cells. Furthermore, both the stemness and aggressive features, along with ALDH(high) percentages were in positive association with the invasiveness of cell lines for sorting, indicating the promotive role of ALDHhigh CSCLs in EOC neoplasia and metastasis, since the whole tumor was derived from the CSCLs with hyperactive self-renewal and aggression. Collectively, this study illustrates the interplay between ALDH(high) CSCLs and EOC invasion, and offers a novel application target for the EOC oncotherapy. (C) 2017 Elsevier Inc. All rights reserved.