  We consider the tails of probability density function (PDF) for the velocity
that satisfies Burgers equation driven by a Gaussian large-scale force. The
saddle-point approximation is employed in the path integral so that the
calculation of the PDF tails boils down to finding the special field-force
configuration (instanton) that realizes the extremum of probability. For the
PDFs of velocity and it's derivatives $u^{(k)} = \partial_x^ku$, the general
formula is found: $ln P (|u^{(k)}|) \propto -(|u^{(k)}|/(Re)^k)^{3/(k+1)}$.
