[en] The structure of the Wilson expansion in the presence of nonleading mass corrections is considered. Renormalization-invariant combinations of the operators G 2/sub μ//sub ν/, mpsi-barpsi, and m 4 are found and their relationship to the anomaly of the trace of the energy-momentum tensor is determined. The connection between the decrease of the strange-quark condensate and the mass corrections∼ m 3/sub s/ln m/sub s/is analyzed qualitatively. The quantity< G 2/sub μ//sub ν/> 0 is calculated in QCD with massive gluons and the effective gluon mass is estimated to be λ (Q 2=∞)= 570 MeV