Local natural persimmons were used as a new precursor to synthesize carbon quantum dots (CQDs) by a brief and environment friendly strategy, hydrothermal method. The as-prepared CQDs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-visible spectroscopy, as well as fluorescence spectrophotometer. The average diameter of CQDs was 2.5±0.5 nm with spherical shape and exhibited blue fluorescence with the maximum emission wavelength at 438 nm and excitation wavelength at 345 nm. The influences of pH and ionic strength on CQDs fluorescence were evaluated. Moreover, the CQDs were used for determination of Fe by blue fluorescence quenching as the result of the interaction between Fe and -OH, -COOH on the CQDs surfaces. The proposed CQDs displayed high selectivity and sensitivity of Fe in comparison with other metal ions. Therefore, a good linear relationship was established with the Fe concentration in the range of 0.6-400 μM. The correlation coefficient of the calibration curve was 0.996. The detection limit of the method was 0.56 μM. Eventually, the CQDs made from persimmons were used for determination of Fe in actual water sample with satisfactory results and gave recoveries between 95.66% and 99.90%. The relative standard deviation was 1.20%-1.86%. The results demonstrated the potential towards diverse applications of the local persimmons.