Compound of ethinylphenylamidine or salt thereof, the compound being represented by the formula (1): ** Formula ** in which R1 and R2 are each hydrogen or C1-12 alkyl, or R1 and R2 can be linked together to form C1-7 alkylene； R3 is hydrogen or C1-4 alkylthio； R4, R5, R6 and R7 are each hydrogen, halogen, C1-4 alkyl, C1-4 haloalkyl or C1-4 haloalkoxy； and R8 is hydrogen； C1-20 alkyl optionally substituted in the alkyl group with one or more substituents independently selected from the group consisting of C1-4 alkoxy, hydroxy, cyano, phenyl, phenoxy and optionally substituted heterocyclic groups； C3-8 cycloalkyl； C1-4 haloalkyl； phenyl optionally substituted on the phenyl ring with one to five substituents independently selected from the group consisting of halogen, C1-6 alkyl, C1-4 haloalkyl, C1-4 alkoxy and phenoxy； a heterocyclic group optionally substituted on the heterocyclic ring with one or more substituents independently selected from the group consisting of halogen, C1-4 alkyl, C1-4 haloalkyl and optionally substituted heterocyclic groups； or - (CH2) n-Si (R9) (R10) (R11), in which R9, R10 and R11 are each C1-6 alkyl, and n is an integer 0 or 1.Compuesto de etinilfenilamidina o sal del mismo, estando representado el compuesto por la fórmula (1):**Fórmula** en la que R1 y R2 son cada uno hidrógeno o alquilo C1-12, o R1 y R2 pueden estar unidos entre sí para formar alquileno C1-7； R3 es hidrógeno o alquiltio C1-4； R4, R5, R6 y R7 son cada uno hidrógeno, halógeno, alquilo C1-4, haloalquilo C1-4 o haloalcoxi C1-4； y R8 es hidrógeno； alquilo C1-20 opcionalmente sustituido en el grupo alquilo con uno o más sustituyentes seleccionados independientemente de entre el grupo que consiste en alcoxi C1-4, hidroxi, ciano, fenilo, fenoxi y grupos heterocíclicos opcionalmente sustituidos； cicloalquilo C3-8； haloalquilo C1-4； fenilo opcionalmente sustituido en el anillo de fenilo con uno a cinco sustituyentes seleccionados independientemente de entre el grupo que consiste en
