This study explores a model of partnership to the success of outsourcing CTI(computer telephony integration) based customer service centers of a telecommunication service company. The motivation of the study is to extend the research on IT outsourcing to IT-enabled BPO of customer service centers as a specific IT outsourcing practice. Previous research on IT outsourcing partnership and success is reviewed for developing an a research model of IT-enabled BPO. This model is proposed based on the previous partnership success models in information systems research. The results of the study confirm major factors related to successful IT-enabled BPO in previous research. Especially, the specificity of a contract and strategic collaboration in partnership are found to be influential on the success of IT-enabled BPO.