Abstract: We considered the problem of neighbor sum distinguishing total colorings of gragh and its related 1-2 conjecture. Firstly, by using the independent decycling set method, we obtained the neighbor sum distinguishing total chromatic numbers of the subdivision graph S(G) and the triangular extension graph R(G). Secondly, when G was an arbitrary simple connected graph and T was a given special graph, we proved that the edge-replaced graph G［T］ satisfied the 1-2 conjecture.

Key words: edge-replaced graph, independent decycling set method, neighbor sum distinguishing total chromatic number, 1-2 conjecture