The Quark Distributions of Baryons

The recent progress in the investigations on the quark structure of the $\Lambda$ and $\Sigma$ baryons are reviewed. It is shown that the quark structure of $\Lambda$ and $\Sigma$ hyperons can provide a new domain to test various theories concerning the spin and flavor structure of the nucleon. The $\Lambda$ and $\Sigma$ Physics might be new directions to explore the quark distributions of baryons both theoretically and experimentally.