  Nonperturbative model of glueball is studied. The model is based on the
nonperturbative quantization technique suggested by Heisenberg. 2- and 4-point
Green functions for a gauge potential are expressed in terms of two scalar
fields. The first scalar field describes quantum fluctuations of the subgroup
$SU(n) \subset SU(N)$, and the second one describes quantum fluctuations of the
coset $SU(N) / SU(n)$. An effective Lagrangian for the scalar fields is
obtained. The coefficients for all terms in the Lagrangian are calculated, and
it is shown that they depend on $\dim SU(n), \dim SU(N)$. It is demonstrated
that a spherically symmetric solution describing the glueball does exist.
