For a few years now, computer science and arti?cial intelligence (AI) have been taking more and more of an interest in social choice. Social Choice Theory is the study of group decision making and is concerned with the design and analysis of methods for collective decision making.
Specifically, Social Choice Theory studies how we should aggregate information about the views, interests, or preferences of individuals into collective decisions, taking into account the minimal conditions that an acceptable aggregation mechanism must satisfy.

In recent years, have been emerged several problems arising from the organization, coordination and management of Multiagent Systems, and one of these problems is the collective decision making.

Social Choice Theory can help to solve the problem of the collective decision making because it is broadly concerned with:
· Designing and analyzing methods for collective decision making.
· Charting the contours of the possibility of such methods.

Two main approaches of Social Choice Theory, relevant for MAS, will be presented :

1. Preference aggregation, which can deal with the problem of aggregation agent’s preferences into one collective preference.
2. Judgement aggregation, which deals on how a group of agents can aggregate individual judgments on connected propositions into a collective judgment on the same propositions; examples of individual judgments aggregation in small groups include committees, panels and tribunals.