OBJECTIVES:To examine the unit cost of inpatient service department of special ward at Banphaeo Hospital that reformed to be Public Organization( the new model) in Thailand. METHODS: Cost analysis from provider's perspective. Cost center was divided by function and the support units in hospitals into three categories: (1)Patient service PS (2) Revenue producing cost center RPCC ; and (3) non revenue producing cost center NRPCC. Total direct costs were composed of labour costs, material costs and capital costs. Indirect costs were allocated by using direct distribution method. RESULTS: The total cost of private ward 4/2 was ␤17,278,303.45 . The total cost in private ward 4/2 consisted of labour cost was ␤3,739,743.60 , material cost was ␤1,242,991.36 Capital cost was ␤2,733,735.87 . The ratio of lobour cost: material cost: capital cost was 48.46: 16.11: 35.43 and ratio of indirect cost was 55.34. The unit cost of inpatient department private ward 4/2 was ␤16,239 per case ; routine service cost was ␤9,226 . 10 and medical care cost was ␤7,012.90 CONCLUSIONS: The results were useful in decision making for resource allocation. It can be used to facilitate comparison of different studies in various type of organization of hospital administration.