Abstract: The samples of cohesive soil containing calcareous nodules (CSCN) with large and corresponding scale sizes have scale effects on the physical and mechanical properties such as compressibility, which are mainly affected by the calcareous nodule content (CNC) and the gradation composition. However, the current researches pay more attention to the influences of the gradation composition on the scale effects, while ignoring those of the CNC. The influences of the CNC on the scale effects of compressibility of the CSCN are discussed, and the relevant mechanism is revealed. The results show that the correlation between the scale effects of compressibility and the CNC is a step curve, which is mainly due to the fact that the calcareous nodules in the samples with the scale size are easier to form the skeleton effects under the same CNC. Based on this, considering the skeleton effects of calcareous nodules, a model for calculating the yield stress and compression index of samples is proposed to reduce the scale effects of samples. The proposed model may provide a new approach to obtain the compressibility parameters of samples with a large size by using the compression test results of samples with the corresponding scale size, which is reliable.