The system to analyze and how to handle clients, in this case is key account, called Key Account Management System. The system which can help a sales person and marketer to be more systematically, understand their clients better and provide a holistic solution. This system can be applied partially or as a whole, depends on the classification of the clients. Key account management system in Resources Sector in MarkPlus,Inc, a leading marketing consulting firm which provide holistic solution for its clients by having a high competitive advantage and broad network internationally and locally. The reason why Resources sector needs a key account management system because pareto exists in the market, only a small number of company holds majority of market share. Therefore, retaining pareto accounts matter, these market leaders are typically large organization with complex decision making unit (DMU), they need complex solutions which require integrated offerings from professional services. The Resources sector also switch to downstream business therefore need to educate the employee about marketing because it is not just about production but also commercial with international standard.Key words : Resources sector, Key Account Management System, MarkPlus,Inc