Abstract: The muddy silty clay is rich in organic matter and widely distributed in Taihu soft soil foundation. It has a large water content and compressibility and is in a state of flow plasticity. All of these make it have bad engineering properties. Based on a pile foundation project which is adjacent to Taihu Lake, through the field pile tests and the p-y curve method of CPTU tests, the lateral bearing characteristics of super-long bored piles in Taihu soft soils and the response laws to the thickness change of muddy soft interlayer are studied. The case study show that the results of numerical calculation from CPTU data agree well with those of the field pile tests, and the load transfer depth is more than 20 m of laterally loaded piles in Taihu soft soils as a result of the influence of muddy soft interlayer. The values and positions of the maximum bending moment and zero point are changed in view of different muddy soft interlayer thicknesses. Within the scope of 0.5~6.0 m, the increment of pile top displacements and the bending moments due to the increasing interlayer thickness decrease. The above research achievements may provide technical supports for the design of laterally loaded piles in Taihu soft soils.