Using DIG (digoxigenin) labeled GAP-43 cDNA as probe, the in situ hybridization method (ISHM) was set up with rat hippocampus slides as positive controls. The change of GAP-43 mRNA levels in the vestibular nucleus area were investigated by ISHM in the labyrinthectomy rats at 5、12、20 and 30 days after the operation. The results demonstrated that labyrinthectomy increased GAP-43 mRNA levels. The application of ISHM laid a foundation for the research of regenerative sprouting, synaptic remodeling and neuroplasticity in the vestibular compensation.