  We construct a model based on social balance theory proposed by Fritz Heider
to analyze the interpersonal network among social agents. The model of social
balance theory provides us an interesting tool to see how a social group
evolves to the possible balance state. We introduce the balance index that can
be used to measure social balance in macro structure level (global balance
index) or in micro structure (local balance index) to see how the local balance
index influences the global balance structure. Several experiments are done and
we discover how the social group can form separation of subgroups in a group or
strengthening a social group while emphasizing the structure theorem and social
mitosis previously introduced.
