A coupling structure of a handrail is provided to make installation simple by fixing upper and lower pipes to a post pipe simply using upper and lower fixing members without welding and fixing cast-iron decoration on the outside of a handrail simply and strongly and to reduce the time and cost required for maintenance by separating and replacing the damaged part easily. A coupling structure of a handrail comprises: an upper pipe(3) provided with a concave part(3a) and fixed to the upper part of a post pipe; a lower pipe(4) provided with a U-shaped joint(4b) and a coupling hole(4c) and fixed to the lower part of the post pipe; cast-iron decoration(1) fixed to the concave part of the upper pipe and the coupling hole of the lower part by forming a coupling projection(2) on the lower part of a rectangular frame(1a) and inserting the coupling projection; a post pipe(5) provided with a fixing hole(5a), a hanging projection and a coupling hole; an upper pipe fixing member(10) composed of a lower fixing plate(11) and an upper fixing plate(15) and inserted to the inside of the post pipe to fix both ends of the upper pipe inserted to the fixing pipe; and a lower pipe fixing member(20) inserted to the inside of the post pipe to fix the lower pipe.
