The Sham Chun River or Shenzhen River (Chinese: 深圳河; pinyin: Shēnzhèn Hé) serves as the natural border between Hong Kong and mainland China, together with Deep Bay, Mirs Bay, and the Sha Tau Kok River.
It formed a part of the limit of the lease of the New Territories in 1898 in the Convention for the Extension of Hong Kong Territory (known also as the Second Convention of Peking).