  This paper reports on polarimetric radiation properties based on the
switching modes of normal PSR B2020+28 by analysing the data acquired from the
Nanshan 25-m radio telescope at 1556 MHz. With nearly 8 hours quasi-continuous
observation, the data presented some striking and updated phenomena. The change
of relative intensity between the leading and trailing components is the
predominant feature of mode switching. The intensity ratio between the leading
and trailing components are measured for the individual profiles averaged over
30 seconds. It is found that there is an excess of high ratios over the normal
distribution, which indicates that two modes exist in the pulsar. The
distribution of abnormal mode has a narrower width indicating that the abnormal
mode is more stable than the normal mode. A total of 76 mode switching events
are detected in our data. It spends 89\% in the normal mode and 11\% in the
abnormal mode. The intrinsic distributions of mode timescales are constrained
with power-law distributions. The significant difference in the index of the
duration distribution between normal and abnormal modes possibly indicates that
the timescale for the abnormal mode to get stable is shorter than that for the
normal mode. The frequent switching between both modes may indicate that the
oscillations between different magnetospheric states are rapid.
