The present invention provides use of protein nog1 in the regulation of the plant yield and/or the grain number per ear. The amino acid sequence of the protein nog1 is as shown in sequence 2. The yield is the yield per plant, and the grain number per ear is the grain number per ear on main stem. Compared with untreated Gui Chao 2, Gui Chao 2 subjected to genetic modification for inhibiting the expression of the protein nog1 has reduced yield per plant and/or reduced grain number per ear on main stem. Compared with untransformed SIL176, a genetically modified plant obtained by introducing a nucleic acid molecule encoding the protein nog1 into SIL176 has increased yield per plant and/or increased grain number per ear on main stem.
