One of the steps taken to maintain and rehabilitate forest resources is to raise conservation funds from drinking water customers, which can be packaged in an environmental services payment scheme or PES. By taking the case of forest resource management in Central Lombok Indonesia, this study used the Contingent Valuation Method to find possible willingness to pay of drinking water customers for environmental service contributions. This study found that the willingness to pay (WTP) of drinking water customers for environmental service contributions that reflecting the economic valuation of Central Lombok Forest resources was an average of Rp. 3,260 (0.23 USD) per month. Factors that influence the magnitude of such values are The Level of Education, Income, Number of family members, and environmental awareness.