In this experiment

the natural rainfall was taken as the erosion power and the standard runoff plot method was used to study the formation of runoff and sediment transport in the longitudinal and cross ridge slope tilled with maize. Results showed that under continuous rainfall conditions

the process of runoff appeared as a “W-type” or an “inverted V-type”

and the sediment formation as a “W-type” or “M-type”. The time length of runoff and sediment yield was the same on the longitudinal ridge

and the total runoff and sediment yield were 1.66~5.80 times and 5.02~5.52 times of those on cross ridge

respectively. There was a significant difference between the peaks of runoff and sediment yield on longitudinal and cross ridges

and the peak phenomenon was found only between cross ridge and rainfall intensity

and 1 min was delayed. The process of runoff appeared as an “inverted V-type” under intermittent rainfall

and the sediment formation were an “inverted V-type” or “M-type”. The runoff and sediment yield on longitudinal ridge were 1.83 times and 2.32 times higher than those on cross ridge

and the first runoff accounted for more than 70% of the total

the sediment yield accounted for 94%~100% of the total. Both cross and longitudinal ridges had the peak phenomenon with rainfall intensity

and the runoff and sediment yield were delayed by 1~4 min with rainfall intensity on longitudinal ridge

1 min on cross ridge. However

there was no peak phenomenon in the rest of rains. Under natural rainfall

the process of runoff and sediment yield was complicated on the longitudinal and cross ridge slopes. These findings could provide a theoretical basis for the prevention and control of soil erosion and the management of water and soil resources in regional sloping fields.