Novel TNFα nanobody was generated with high affinity and low molecular weight. TNFα nanobody inhibited increased migration and invasiveness of MCF-7 and MDA-MB-231. Combining Taxol with TNFα nanobody enhanced anti-tumor efficacy. TNFα nanobody inhibited mice 4T-1 tumor EMT. TNFα nanobody penetrated into and neutralized TNFα interior tumor.