Karst valley area is prone to soil and water loss during rainfall

which destroy the ecological environment of the area. This study taken the karst valley area as the research object

through indoor simulation of its typical bedding/inverse layer slope characteristics and the development degree of underground hole crack and using artificial rainfall test

the characteristics of the surface underground runoff production under different rainfall conditions were studied

thereby revealing the production mechanism of surface and underground runoff in karst valley. The results showed that: (1) The surface underground runoff yield and discharge in the karst valley area was affected by rain intensity

and the underground runoff yield and discharge was greater than the surface runoff under light rain (30 mm/h)

and the surface runoff yield and discharge increased under moderate rain (60 mm/h)

meanwhile it was greater than underground runoff under the condition of large and bare slope. Under the condition of heavy rain (90 mm/h)

the surface runoff yield and discharge were both greater than the underground runoff on bare slope and bedding slope. (2) The development degree of underground pore fissures impacted the distribution ratio of surface underground runoff yield and discharge. The larger the degree of underground pore fissure was

the greater the underground runoff yield and discharge would be

and the distribution proportion of surface underground runoff yield and discharge would change when the underground hole fissure degree was 2%~3%. (3) Under different strata tendencies

the surface runoff yield and discharge and its distribution ratio were the highest on bare slopes

and the lowest on reverse slopes

while the underground runoff yield and discharge and its distribution ratio were the highest on reverse slopes

and the lowest on bare slopes. (4) Under different strata inclination angles

the surface runoff yield and discharge was the maximum on the bedding layer of 30°

and the lowest on the bedding layer of 90°

while the underground runoff yield and discharge was opposite. For the reverse slope

the surface runoff yield and discharge was the maximum on the slope of 90°

and the minimum on the slope of 60°

the underground runoff yield and discharge was the highest on the slope of 60°

and the lowest on the slope of 90°. The results could provide scientific basis for further understanding of the production mechanism of surface and underground runoff in the karst valley area.