The last decade, using of the Decision Support System (DSS) in most hospitals institution are very limited. in general, the decision making only emphasis to the physicians's knowledge and no considearation of existed database as a reference to make a decision. in this condition, the possibility to make a mistake or inconsistency in decision making is very often happened. therefore we need a system that can handle and help the physician in decision taking so that error or inconsistency in decision taking can be reduced. in this paper, data mining technique is implemented to able in creating deep query that can optimize utilizing of huge data such as data warehouse. result of data mining can produce more valuable information that reduced inconsistency in decision making. we can obtain the data, combining, and fine the hidden pattern in the collected data and use that information to help the physician to make a decision.