  We discuss how to implement the source terms in Quantum Chromodynamics (QCD)
respecting gauge invariance and noncommutativity of color charge density
operators. We start with decomposing the generating functional of QCD into
constituents projected to have specified color charge density. We demonstrate
that such a projection leads to the gauge invariant source terms consisting of
a naive form accompanied by the density of states which cancels the gauge
dependence. We then illustrate that this form is equivalently rewritten into a
manifestly gauge invariant expression in terms of the Wilson line. We confirm
that noncommutativity of color charge density operators is fulfilled in both
representations of the source terms. We point out that our results are useful
particularly to consider the problems of the quantum evolution in high energy
QCD.
