Abstract: Hemoglobins exist throughout the organism kingdom, plant hemoglobin plays critical roles in plant nitrogen fixation, embryogenesis and defense responses.In recent years, research on plant hemoglobin classification and its nwe function of plant cell fate determination in gene regulation pathway is quite active.In this paper, we introduced new nomenclature system of plant hemoglobin, and reviewed the latest research achievements of symbiotic hemoglobin (sHb), non-symbiotic hemoglobin (nsHb) and truncated hemoglobin(tHb);which would help to comprehensively elucidate the molecular mechanism of plant hemoglobin.