PROBLEM TO BE SOLVED: To provide a new herbicide safe for cultured plants, showing remarkable herbicidal activity to weeds, having practical residual effect and not remaining into the soil more than necessary, and exerting bad influence on the environment.SOLUTION: Provided is an arylsulfonamide based compound represented by formula (I) or its salt. [Rdenotes halo C-Calkyl; Rdenotes H, C--Calkyl or the like; Rdenotes halogen, C-Calkyl or the like; Rand Rdenote H, C-Calkyl or the like; T denotes halogen, C-Calkyl or the like; W denotes O or S; X denotes -O-Y, -S-Z, - or the like; Y denotes substituted C-Calkyl, substituted C-Calkyl carbonyl or the like; Zdenotes H, hydroxy C-Calkyl, C-Calkoxy C-Calkyl or the like; m denotes the integer of 0 to 4; and n denotes the integer of 0 to 5.SELECTED DRAWING: None【課題】栽培植物に安全で、雑草に対する著しい除草活性を示し、実用的残効性と必要以上の土壌中への残留せず、環境への悪影響を及ぼさない新規な除草剤の提供。【解決手段】式(I)で表されるアリールスルホンアミド系化合物又はその塩。[R1はハロC1-C6アルキル;R2はH、C1-C6アルキル等;R3はハロゲン、C1-C6アルキル等;R4及びR5はH、C1-C6アルキル等;Tはハロゲン、C1-C6アルキル等;WはO又はS;Xは-O-Y、-S-Z1、-等;Yは置換されたC1-C6アルキル、置換されたC1-C6アルキルカルボニル等;Z1はH、ヒドロキシC1-C6アルキル、C1-C6アルコキシC1-C6アルキル等;mは0~4の整数;nは0~5の整数]【選択図】なし