  We give a generalized Lagrangian density of 1+1 Dimensional O(3) nonlinear
sigma model with subsidiary constraints, different Lagrange multiplier fields
and topological term, find a lost intrinsic constraint condition, convert the
subsidiary constraints into inner constraints in the nonlinear sigma model,
give the example of not introducing the lost constraint, by comparing the
example with the case of introducing the lost constraint, we obtain that when
not introducing the lost constraint, one has to obtain a lot of various
non-intrinsic constraints. We further deduce the gauge generator, give general
BRST transformation of the model under the general conditions. It is discovered
that there exists a gauge parameter originating from the freedom degree of BRST
transformation in a general O(3) nonlinear sigma model, and we gain the general
commutation relations of ghost field.
