Abstract: W₁₈O₄₉ nanoparticles were first prepared by solvothermal method using tungsten chloride (WCl₆) and gadolinium (Gd) nitrate (Gd(NO₃)₃·6H₂O) as raw materials, then the gadolinium chelated tungsten oxide (W₁₈O₄₉-DTPA/Gd) nanocomposites were fabricated by microemulsion method. The structure and morphology were characterized by XRD, SEM and TEM. The results reveal that samples possess high crystallinity, good dispersion, spindle morphology the length is about 640 nm and the width is about 160 nm. And the W and Gd elements are distributed in the samples uniformly. The test of photothermal properties show that the temperature of the aqueous solution can increase to 46.9 C under the near-infrared light of 808 nm for 10 min that can meet the requirement of photothermal treatment of cancer. At the same time, the temperature of the pure water in the control group hardly changes. In addition, the samples also have computer tomography (CT) imaging function, the imaging effect is strengthened with the increase of the concentration. Compared with pure W₁₈O₄₉, the imaging effect has no obvious change. After co-cultured with samples for 24 h, The Human normal stem cells (LO2) survival rate is still above 85% at different sample concentrations.