A series of VO2 (B) nanostructures with different morphologies including nanobelts, urchins, and carambolas were hydrothermally synthesized and explored as catalyst precursors for ammoxidation of dichlorotoluene to optimize the structural properties. The catalytic results show the performance decreases in the following order: nanobelts> urchins> carambolas. On this basis, Cr doped VO2 (B) nanobelts were prepared and showed the yields of 2,6-dichlorobenzonitrle reaching up to 71.5%. This study provides valuable guidance on the design and development of highly effective ammoxidation catalysts.