Based on the structural theory of Petri nets, the boundedness and liveness monotonicity of a
subcategory of asymmetric choice (AC) nets, new extended strong asymmetric choice (NESAC) nets, were
studied. The sufficient and necessary condition for determining structural liveness and boundedness of an
NESAC net is that N is covered by a cluster of siphons and every nonemptyminimumsiphon must be a trap
and satisfiest ∩H=t ∩H=1.NESAC net has the same characteristic of liveness monotonicity
as ESAC net does.