In order to study the effects about the roadside landscape of prairie highway on drivers" heart rate variability (HRV), the real road test is conducted on the prairie highway. The drivers’ ECG signal is collected by multiple physiological recorder MP150 in the process of driving. Combined with the theoretical research of physiology and ergonomics etc., based on the time and frequency domain analysis of HRV, the drivers’ HRV is analyzed on the different roadside landscape environment. The results show that the drivers’ RMSSD which is time domain index of R-R phase present smooth fluctuations in smaller scale and there is no significant difference between the average on the two types of roadside landscape; The LF/HF present more larger change in landscape Ⅱ and there is a significant difference between the average on the two types of roadside landscape; The drivers’ mental load is larger relatively on monotonous roadside landscape.