Abstract: In this paper, mercaptopropionic acid modified CdTe quantum dots and Jasmonic acid (JA) were coupled to the surface of Fe3O4 nano particle, thus magnetic fluorescent nanoprobe with high fluorescence properties, strong magnetic response and specific labeling of JA receptor was synthesized. The fluorescence spectra proved that the probe maintained the superior fluorescence properties of CdTe quantum dots such as high fluorescence intensity, wide pH range of application, good anti- photobleaching properties. The hysteresis loop test shown the probe had good magnetism response performance. The probe was then utilized to image the JA receptor in protoplast of mung bean. The results indicated that this probe had high selectivity to the JA receptor and the JA receptor was mainly existing in the protoplast membrane. The labeling approach was convenient and could offer the visual information for the signal transduction study of JA.