Hot electrons produced in the ultra-intense laser-plasma interactions play very important roles in the scheme of “fast ignition”. Bremsstrahlung measurements can be an effective method to diagnose the hot electrons accelerated in the forward direction. The transport of the hot electrons and the characteristics of the bremsstrahlung photons were calculated using the Monte Carlo electron-photon transport code MCNP. The feasibility of the bremsstrahlung diagnostic method in laser plasma interactions is also discussed.