We have investigated the escape rate of nano-magnetic particle with a magnetic field applied along the easy axis. The model studied here is described by the Hamiltonian H=$K_1hat{S}{_z^2}$ ＋ $K_2hat{S}{_y^2}$ ＋ $g{mu}_bB$ $hat{S}_x(K_1>K_2>0)$ and the escape rate was calculated with in the semiclassical approximation. We have obtained a diagram for orders of the phase transition depending on the anisotropy constant and the external field. For $K_2$/$K_1>$0.85 the present model reveals the existence of the first order transition within the quantum regime.