The famous graph theory expert Erds and Neetǐil conjectured that strong edgecoloring number of a graph is bounded above by 〖SX(〗5〖〗4〖SX)〗Δ2 when Δ is even and 〖SX(〗1〖〗4〖SX)〗(5Δ2－2Δ+1) when Δ is odd. They gave a graph of Δ=4. In this paper, we construct a series of such graphs, and prove that if the Strong Edge Coloring Conjecture is correct, the boundary number is optimum when Δ is odd.