Abstract: Calcium lignosulfonate (CL) was used to fill high density polyethylene (HDPE) to prepare CL/HDPE composites, the composites were characterized by SEM, DSC, XRD, and the mechanical properties such as strength, creep behavior and stress relaxation of CL/HDPE composites were tested. The results show that the CL/HDPE composites have good the bonding interface and the thermal stability; the addition of CL can improve the flexural strength, but it can lead a negative effect on the impact strength of CL/HDPE composites; the increase of CL content can improve the creep resistance and stress relaxation, but the increase of temperature can lead a negative effect on the creep behavior and stress relaxation of CL/HDPE composites.