An inhibitor for tobacco axillary bud growth, said inhibitor comprising, as the active ingredient, one or more kinds of ultra-long chain fatty acid synthesis inhibitors such as a chloroacetamide-based herbicide, fentrazamide, cafenstrole or indanofan; an inhibitor for tobacco axillary bud growth, said inhibitor comprising the aforesaid ultra-long chain fatty acid synthesis inhibitor together with clorthal-dimethyl or an aliphatic alcohol having 6 to 20 carbon atoms; and a method for inhibiting tobacco axillary bud growth which comprises applying said inhibitor for tobacco axillary bud growth. This inhibitor for tobacco axillary bud growth shows sustained drug efficacy at a low concentration, induces neither chemical injury nor disease, and can contribute to the improvement in labor productivity.