To study the impact of road conditions and gradients on fuel consumption and pollutant emission characteristics of light-duty gasoline vehicles in plateau environment, a China Ⅵ light-duty gasoline vehicle was selected as the subject. Based on the custom RS 803 test cycle that was independently developed by coupling "speed and gradient" by using real-world road operation data, fuel consumption and pollutant emission tests were conducted under normal temperature conditions at the Light-Duty Vehicle Environmental Simulation Emission Laboratory of the National Plateau Motor Vehicle Quality Inspection and Testing Center (altitude 1 914 m). By comparing test conditions with and without gradients, the influences of vehicle operating conditions and road gradients on fuel consumption and pollutant emission characteristics of light-duty gasoline vehicles were analyzed. The results indicate that the relative deviations in CO₂ emissions and fuel consumption between the RS803 cycle with and without gradients are 1% and 2% respectively, suggesting that road gradients have a minor impact on vehicle fuel consumption. However, gradients have a significant effect on pollutant emissions. Under gradient conditions, THC, CO, N₂O and NO_x emissions increase by 27%, 58%, 50% and 3% respectively compared to conditions without gradients. The fuel consumption and CO₂ emissions show a strong positive correlation with speed, acceleration and vehiclespecific power (VSP), with correlation coefficients of 0.55 and 0.53 for VSP respectively. CO emissions exhibit an extremely strong correlation with speed, and higher speeds will lead to more CO emissions. N₂O and NO_x emissions show lower correlations with these factors. Optimizing combustion strategies under highspeed conditions can reduce CO emissions, but this requires balancing the local increasing trends of NO_x and N₂O.