Transition metal doped CdS and ZnS dilute magnetic semiconductors have attracted widespread research interests due to their potential spin electron applications. Most of these theoretical and experimental analyses have focused on studying their optical properties. In response to the widespread application of dilute magnetic semiconductor nanomaterials in electronic components, semiconductor chips, integrated circuits, and other fields, based on solvent thermal method,the dilute magnetic semiconductors with room temperature ferromagnetic Cr-doped CdS and ZnS nanostructures were synthesized by solvothermal method. According to X-ray diffraction (XRD) analysis, the products of Cr-doped CdS and ZnS were clearly determined to the hexagonal phase. Scanning electron microscopy (SEM) images showed that morphologies of the CdS and ZnS with different contents chromium were mainly nanorods and micro floral shape. Energy dispersive spectroscopy (EDS) measurements indicated that the synthesized products were composed of Cr, Cd, Zn and S. The vibrating sample magnetometer (VSM) showed that undoped CdS exhibited weak ferromagnetism at room temperature, undoped ZnS exhibited diamagnetism, while Cr-doped CdS and ZnS had strong ferromagnetism. The saturation magnetizatio M s of Cr-doped CdS(Cr=4.21%) was about 9.524 (10−3 emu/g), the coercivity ofH c was about 98.327 Oe. The saturation magnetization M s of Cr-doped ZnS (Cr=7.67%) was about 8.502 (10−3 emu/g), the coercivity of H c was about 96.237 Oe. The ferromagnetism of Cr-doped CdS and ZnS were attributed to the duoble exchange mechanism.