  In the pure scattering theory, the universality of the soft limit has been
studied for a long time. In this talk we review the property of soft limit to
relate an $n$-point amplitude to an $(n-1)$-point amplitude. We show how this
property can be used to decompose amplitudes into different complementary soft
channel. The existence of such decomposition provides a new way to understand
how to construct amplitude solely from them soft limit.
