Simply supported reinforced concrete （RC） beams without web reinforcement under asymmetric concentrated load have two different shear span-depth ratios， while the relationship between the shear capacity and the shear action of each shear span is uncertain. An experimental study on the shear behavior of 6 simply supported RC beams without web reinforcement under asymmetric concentrated load and 4 specimens subjected to symmetric concentrated load was carried out. The failure patterns， load-midspan displacement curves and the strains of longitudinal tensile reinforcement were obtained. Moreover， the applicability of the corresponding formula in the Chinese code for design of concrete structures （GB 50010—2010）， the modified compression field theory， the strain-based shear strength model and Zsutty’s formula were analyzed. The results indicate that when the small shear span-depth ratio of simply supported RC beams without web reinforcement is always 1.0 and the large shear span-depth ratios are from 2.0 to 4.0， the shear failure occurs in the larger shear span. When the larger shear span-depth ratio increases from 3.0 to 3.5， the ultimate load capacity of the beam is controlled by the smaller shear span changed from being controlled by the larger shear span. The locations of shear failure in simply supported RC beams without web reinforcement under asymmetric concentrated load predicted by GB 50010—2010 are opposite to the experimental results， while Zsutty’s formula provides a less biased prediction.