By using JETSET 7.2 as e+e- event generator at different c.m. energies
, we studied single jet multiplicity distributions in different rapidi
ty and p(T) intervals. Good NB behavior is found and related clan stru
cture analysis is performed. Observed differences in the behavior of t
he 2- and 3-jet samples can be understood in terms of the relative con
tribution of single quark and gluon jet to the 3-jet sample, which are
obtained by selecting event by event in this sample the highest and t
he lowest energy jet respectively.