Abstract: This study isto demonstrate the interaction between the thyroid hormone receptor（THR）and the Drosha protein. Selecting HEK293 cells as materials，the protein immune complexes were acquired by co-immunoprecipitation method，and then detected by Western blot and analyzed by mass spectrometry. The results showed that there was THR protein detected by THR antibody Western blot，and Drosha protein was detected by Drosha antibody Western blot. Concurrently，the Drosha protein was identified by mass spectrometry after immunoprecipitation with THR antibody，and the mass spectrometry after Drosha antibody immunoprecipitation confirmed that therewas also a THR protein，suggesting that there was interaction between the THR and the Drosha protein. Moreover，the Go cluster analysis for the primarily screened 54 proteins interacting with both THR and Drosha protein revealed that the identified proteins were mainly composed of cell membrane and nucleus，and they were involved in varied biological pathways such as cell migration，cell apoptosis，protein metabolism，immune responses，signal pathways and transcription regulations，etc.，also had molecular functions of binding with nucleic acid and cytoskeleton.

Key words: thyroidhormone receptor, Drosha protein, co-immunoprecipitation, mass spectrometry, HEK293 cell line