The present invention provides a composition for modulating invasion ability of a tumor, comprising: an effective amount of an activator for a miRNA-mediated pathway or an effective amount of a modulating member in the miRNA-mediated pathway being a modulating member, and wherein the miRNA-mediated pathway is regulated by at least one miRNA selected from the group consisting of miR-346, miR-504 and miR-1179. The composition functions according to a novel model that an activator or a modulating member can regulate cellular invasion/migration of tumor via a miRNA-mediated pathway, and thereby can be a potential candidate of molecular drug to treat the tumor by modulating its invasion ability. A method for treating or preventing tumor invasion method is provided as well. Meanwhile, a method for detecting the invasive ability of a tumor in a subject and the kit thereof are also provided.