Objective：To construct CDs@Tf fluorescent nanoprobe based on carbon dots，and to explore the material preparation and the potential application in fluorescence imaging of ovarian cancer cells. Methods：Using sodium citrate dihydrate and urea as raw materials，a high efficiency fluorescent carbon dots（CDs）were prepared by solvent-free method at high temperature. The cell cytotoxicity of CDs was determined by MTS assay against HO-8910 ovarian cancer cells and EA.hy926 umbilical vein endothelial cells. Major organs（heart，lung，kidney，liver，spleen） were collected from Kunming mice after 7 days and 21 days of CDs injection via tail vein for histological analysis to evaluate the toxicity of CDs in vivo. Using 1-（3-dimethylaminopropyl）-3-ethylcarbonide diimine hydrochloride（EDC·HCl） and N-hydroxysuccinimide（NHS） as chemical coupling agents，the prepared CDs were covalently combined with transferrin（Tf） to form fluorescent molecular probe CDs@Tf. The probe was characterized and applied to cell imaging. Results：The spherical fluorescent CDs with an average diameter of 3.85 nm were prepared. The CDs exhibited an optimal excitation wavelength of 400 nm and a maximum emission wavelength of 520 nm，and a quantum yield of 93%. The CDs had excellent properties such as high fluorescence intensity and low cytotoxicity. The established CDs@Tf molecular probe could target and identify HO-8910 ovarian cancer cells. Conclusion：A novel targeted fluorescent nanoprobe CDs@Tf with excellent optical performance and low toxicity is successfully constructed，which is helpful for the early screening of ovarian cancer.