Multiferroics of spin origin, for which magnetic long-range order and electric polarization occur simultaneously, have attracted considerable interest. The strong coupling between magnetism and ferroelectricity, a greatly desirable asset for potential applications in spintronics, is often found in a material with complex spin structure. Knowledge of the magnetic structure is required to predict and exploit novel multiferroic materials via symmetry analysis based on some underlying mechanisms of multiferroicity put forward in theoretical works. Neutron diffraction is a wonderful technique to uncover these complex magnetic structures. We intend to reveal the magnetic structure of single crystal NaFeGe2O6 under magnetic field.