Gold (Au) nanomaterials are promising photothermal agents for the selective treatment of tumor cells owing to the strong capability to convert near-infrared (NIR) irradiation into heat energy. One basic issue for practical photothermal therapy is the enhancement of photothermal effect in NIR region. Here, various low-molecular-weight thiols are applied to induce one-dimensional (1D) self-assembly of Au nanorods (NRs), which leads to the redshift of absorption peak towards NIR region. As a result, the 1D assembled Au NRs exhibit improved photothermal effect at 808 nm in comparison to unassembled Au NRs.