To provide a novel pesticide. The present invention provides a pesticide containing a pyridyl-triazolopyrimidine derivative represented by the formula (I) or its salt as an active ingredient: wherein R1 is substitutable alkyl, substitutable cycloalkyl, substitutable alkenyl, substitutable alkynyl, halogen, cyano, aryl, a heterocyclic group which may be substituted by alkyl, OR2, S(O)n#191R3? or NR4R5； R2 is hydrogen, alkyl, alkenyl, alkynyl, haloalkyl, alkoxyalkyl, acetyl or aryl； R3 is alkyl or acetyl； R4 is hydrogen or alkyl； R5 is hydrogen, alkyl or the like； X is alkyl, alkenyl, alkynyl, halogen, haloalkyl, cyano, nitro or the like； m is an integer of from 1 to 4； and n is an integer of from 0 to 2.
