The core region of the Shapley Supercluster is dominated by three rich Abell clusters and two poor clusters .
Since these member clusters are expected to be evolving rapidly in comparison to nonmember clusters because of the high merging rate , it is important to study the member clusters for understanding of the cluster evolution .
Since the spatial distributions of gas temperature and metal abundance in each member cluster provide us with information on the interactions and motions of member clusters , they are useful for understanding their dynamics .
From the results of eight ASCA pointing observations ( total \sim 
300 ksec ) of the core region , we obtained parameters of gas temperature , metal abundance , and X-ray luminosity for five member clusters and found that they are similar to the other field clusters not belonging to superclusters observed with ASCA .
This result and the mean gravitational mass density of the core region indicate that the members are growing in the same way as the non-member clusters , and the core of the supercluster is just on the way to contraction .
Based on analyses of detailed spatial structures with a 4 ^ { \prime } \times 4 ^ { \prime } scale , the two poor clusters show nearly isotropic temperature distributions , while the three Abell clusters are asymmetric .
A3558 was analyzed with a 2 ^ { \prime } \times 2 ^ { \prime } 
scale , owing to the statistical advantage , and it was revealed that A3558 has clear asymmetric distributions of gas temperature and X-ray surface brightness .
This is thought to be caused by cluster-cluster mergings and/or group infallings .
A metal-rich region with the size of \sim 320 h _ { 50 } ^ { -1 } kpc was also found to the southeast , \sim 
12 ^ { \prime } away from the cluster center of A3558 .
It is expected that either a remnant of a merged core has been left after a major merging or a group of galaxies has been recently infalling .
Thus , the high dynamical activity of A3558 is proved .