Economic valuation of grassland ecosystem services is important for protecting and restoring grassland ecosystems. This study aims to investigate Chinese netizens’ willingness-to-pay (WTP) for protecting grassland ecosystem services in Inner Mongolia by using the contingent valuation method. The results indicate that 61.55% of respondents expressed a positive WTP. The mean WTP was estimated to be CNY 170.76 (USD 25.11) per person per year. We found that there is a significant spatial difference in respondent’s WTP. Factors such as respondent age, education, household income and concern about grassland protection significantly affected their WTP. Younger, more educated and wealthier respondents have a higher probability of willingness to pay, and those who are concerned about grassland protection present a higher WTP. The regression results also show that distance from the grassland negatively affects the probability and values of people’s WTP. Findings of this research provide useful policy implications for decision-makers involved in grassland protection and management.