In this study, two novel glucose dithiocarbamates (3a and 3b) were successfully synthesized via a “click chemistry” route and then radiolabeled with a [^99mTcN]²⁺ core to prepare the corresponding ^99mTcN complexes in high yields. Both of them were hydrophilic and had good in vitro stability. The in vivo biodistribution studies in mice bearing S180 tumor showed that the complexes accumulated in the tumor with high uptake and good retention. Through comparison, ^99mTcN-3b had the advantages of higher tumor uptake, tumor/blood and tumor/muscle ratios at 2 h post-injection. The single-photon emission computed tomography (SPECT) image studies of ^99mTcN-3b showed obvious radioactive uptake in the tumor region and the tumor-to-non-target ratio was high, suggesting that it could be regarded as a promising tumor imaging agent.