PROBLEM TO BE SOLVED: To provide a novel noxious organism control agent, particularly a bactericidal agent and a nematicidal agent.SOLUTION: The present invention provides an N-alkenyl-substituted amide compound represented by formula (I) or a salt of the compound, and a noxious organism control agent comprising them. In the formula, Grepresents a structure represented by G-3, G-7 or the like; Grepresents a structure represented by G-1; W represents an oxygen atom or the like; Xrepresents difluoromethyl, trifluoromethyl or the like; Xrepresents a hydrogen atom or the like; Yrepresents a halogen atom or the like; Yrepresents a hydrogen atom, a halogen atom, methoxy or the like; Yrepresents a halogen atom, trifluoromethyl, C-Calkynyl, (C-C) alkynyl optionally substituted by R, or the like; Yand Yindependently represent a hydrogen atom, a halogen atom or the like; Rand Rindependently represent a hydrogen atom, a halogen atom, methyl, or the like; Rand Rindependently represent a hydrogen atom, methyl or the like; Rrepresents a hydrogen atom or the like; and Rrepresents C-Ccycloalkyl, trimethylsilyl, phenyl or the like.【課題】 新規な有害生物防除剤、特に殺菌剤及び殺線虫剤を提供する。【解決手段】 式(I):【化1】[式中、G1はG1-3、G1-7等で表される構造を表し、G2はG2-1等で表される構造を表し、Wは酸素原子等を表し、X1はジフルオロメチル、トリフルオロメチル等を表し、X2は水素原子等を表し、Y1はハロゲン原子等を表し、Y2は水素原子、ハロゲン原子、メトキシ等を表し、Y3はハロゲン原子、トリフルオロメチル、C2~C6アルキニル、R7によって任意に置換された(C2~C6)アルキニル等を表し、Y4及びY5は各々独立して水素原子、ハロゲン原子等を表し、R1及びR2は各々独立して水素原子、ハロゲン原子、メチル等を表し、R3及びR4は各々独立して水素原子、メチル等を表し、R5は水素原子等を表し、R7はC3~C6シクロアルキル、トリメチルシリル、フェニル等を表す。]で表されるN-アルケニル置換アミド化合物又はその塩、及びそれらを含有する有害生物防除剤。【選択図】 なし