An object of the present invention is to provide an anti-tumor agent and an anti-tumor kit which have superior anti-tumor effect as compared with a therapy with gemcitabine, paclitaxel or a combination thereof； as well as an anti-tumor effect enhancer. According to the present invention, provided is an anti-tumor agent including paclitaxel or a salt thereof and 1-(2-deoxy-2-fluoro-4-thio-β-D-arabinofuranosyl)cytosine or a salt or prodrug thereof.
