The BRCAA1-conjugated fluorescent magnetic nanoprobes exhibit very low-toxicity, lower magnetic intensity and lower fluorescent intensity with peak-blue-shift than pure FMNPs, could be endocytosed by gastric cancer MGC803 cells, could target in vivo gastric cancer tissues loaded by mice, and could be used to image gastric cancer tissues by fluorescent imaging and magnetic resonance imaging, and mainly distributed in local gastric cancer tissues within 12 h post-injection. This evidence concerns the gene ARID4B and gastric cancer.