  On the base of Diffusion Monte-Carlo method it is developed a new Complex
Diffusion Monte-Carlo (CDMC) method allowing to simulate the quantum systems
with complex wave function. There are no approximations on the calculation of
modulus and phase of wave function in contrast to other methods. We find that
the averaged value of any quantity in CDMC will have no direct contribution
from the phase of the distribution function but only from the phase of the
Green function of the diffusion equation. This is most important and crucial
point of CDMC. We are testing CDMC by the calculation of the wave function and
the ground state energy of two-dimensional electron placed into the external
uniform magnetic field. There is an excellent agreement between simulations
results and an analytical ones.
