  With the help of 3D MHD simulations we investigate the collapse and
fragmentation of rotating turbulent prestellar core embedded into turbulent
medium. The numerical code is based on a high resolution Godunov-type
finite-difference scheme. Initial turbulence is represented by the ensemble of
Alfven waves with power law spectrum. Our computations show that under
realistic parameters two bound fragments can appear when the density increases
at $100-10^3$ times. The distance between the fragments is about $0.1$ of the
initial core radius and their orbital period is comparable to the initial free
fall time of the core. These results can explain the origin of binary stars
with separation $0.001-0.01$ pc in the Galaxy field.
