  Observations of magnetic helicity transportation through the solar
photosphere reflect the interaction of turbulent plasma movements and magnetic
fields in the solar dynamo process. In this chapter, we have reviewed the
research process of magnetic helicity inferred from the observed solar magnetic
fields in the photosphere and also the solar morphological configurations with
solar cycles. After introducing some achievements in the study of magnetic
helicity, some key points would like to be summarized.
  The magnetic (current) helicity in the solar surface layer presents a
statistical distribution similar to that of the sunspot butterfly diagram, but
its maximum value is delayed from the extreme value of the sunspot butterfly
diagram and corresponds in the phase with the statistical eruption of solar
flares. During the spatial transport of magnetic (current) helicity from the
interior of the sun into the interplanetary space at the time-space scale of
the solar cycle, it shows the statistical distribution and the fluctuation with
the hemispheric sign rule. These show that the current helicity and magnetic
helicity transport calculation methods are complementary to each other.
  We also notice that the study of the inherent relationship between magnetic
helicity and the solar cycle still depends on the observed accuracy of the
solar magnetic field.
