In order to study the effect of mechanical behavior of steel H-pile foundation in integral abutment jointless bridges (IAJBs) by unbalanced earth pressure and asymmetric loading, several reciprocating low-cycle pseudo-static tests on studying the soil-steel H-pile interaction were carried out under symmetric conditions (both balance earth pressure and symmetric loading), only unbalance earth pressure (symmetric loading) and completely asymmetric conditions (both unbalance earth pressure and asymmetric loading), respectively. A comprehensively comparative study was performed to find their behaviors in terms of horizontal deformations, soil resistance, strain, and bending moment of piles. The test results indicate that the horizontal deformation of positive loading is signifi cantly different from that of negative loading under completely asymmetric conditions. In addition, the soil resistance and bending moment of the pile are significantly larger than those of negative loading under positive loading. The un? balance earth pressure and asymmetric loading have a significant impact on the horizontal deformations, soil resis? tance, and the bending moment of the pile. Among them, the unbalance earth pressure induces the overall negative ac? cumulative deformation and increases the soil resistance and the bending moment of the pile. The positive asymmetric loading decreases the horizontal deformation but increases the soil resistance and bending moment of the pile. The negative asymmetric loading decreases the horizontal deformation, soil resistance and bending moment of the pile.