Field test and numerical analysis were conducted to investigate the soil stress variation and lateral pile response to whole excavations from cone penetration tests (CPTs). The effects of excavation unloading on the performance of CPT cone resistances and p-y curves were examined. The p-y responses were related to the excavation-induced both stratigraphic variation and soil stress relief. Based on CPT profiles, the numerical calculations of the lateral pile responses before and after excavations were obtained and compared using a CPT-based p-y method. Finally, the suggestion on the design of laterally loaded piles considering excavation unloading was given.