  The evolution of $N$ spin-$1/2$ system with all-range Ising-type interaction
is considered. For this system we study the entanglement of one spin with the
rest spins. It is shown that the entanglement depends on the amount of spins
and the initial state. Also the geometry of manifold which contains entangled
states is obtained. Finally we find the dependence of entanglement on the
scalar curvature of manifold and examine it for different number of spins in
the system.
