Let G = ( V , E ) be a simple, finite, connected, weighted graph satisfying curvature condition C D E ′ ( n , 0 ) and polynomial volume growth V ( x , r ) ≤ c 0 r m , Δ η be the normalized Laplacian. In this paper we prove that the semilinear heat equation u t = Δ η u + u 1 + α on G has no non-negative global solutions for any bounded, non-negative and non-trivial initial value in the case of m α = 2 . The obtained result provides a significant complement to the work that was done recently by Lin and Wu (2017) concerning the existence and nonexistence of global solutions for the semilinear heat equation on graphs. [ABSTRACT FROM AUTHOR]