  The weak decays of hyperons and hypernuclei are studied from the chiral
symmetry viewpoint. The soft pion relations are useful in understanding the
isospin properties of the weak hyperon decays. Recent development on the
short-range part of the $\Lam N\to NN$ weak transitions shows fairly good
account of the weak decays of hypernuclei, though it fails to explain the $n/p$
ratio. The $\pip$ decays of light hypernuclei are studied in the soft pion
approach. They are related to the $\DI=3/2$ amplitudes of the nonmesonic decay.
