The present invention relates to: an indole derivative, which is a novel cell mitosis inhibitor; a stereoisomer thereof or a pharmaceutically acceptable salt thereof; a use thereof as a therapeutic agent; a composition containing the same and a treatment method using the composition; and a preparation method therefor. According to the present invention, the indole derivative, the stereoisomer thereof or the pharmaceutically acceptable salt thereof, inhibits the tubulin polymerization during mitosis so as to induce apoptosis, and has an excellent anti-cancer effect also in cancer cells having multiple drug resistance.