||Hong Kong Hospital Authority operates a large number of hospitals and clinics with identical or similar services and are distributed throughout different districts. However, with continuing economic and urban development, the population base and demography may change significantly as well as the factors such as patient preference, location of work and so on, an unbalanced situation between healthcare demands and hospital capacity within the district is created. In the unbalanced situation of demands and capacity, the waiting time for the patient becomes longer and the health care resources are not fully utilized. This will results in deterioration of service quality and the resources utilization of health care system. In such situation, if the hospitals have a good patient flow policy to refer the patient to receive treatment in other hospitals/clinics that are not fully utilized, this will be beneficial both the patients and hospitals. The patient will be able to receive the same services with a shorter waiting time and the hospital can release the burden to other hospitals in other districts and increase the utilization of other hospitals at the same time. In this study, a heuristic algorithm focusing on the patient flow among hospitals/clinics was introduced through the simulation study, which can be extended to multi-hospital. This heuristic algorithm will give a satisfactory control policy for the patient flow among the clinics in order to minimize the overall-wide total cost from the system point of view. In this algorithm, we consider there are three options of decision on the arrival of patient to the multi-site hospital. They are: receiving the service at their local clinic, switching to clinic in other region or leaving the system.