He told Uighurs to prepare for a holy war or Jihad and urged a "vast media campaign" to raise awareness of their fate at the hands of "oppressive" China.
In the video posted to jihadist websites, Abu Yahya al-Libi appeared to launch a frontal assault against China.
"This massacre is not being carried out by criminal Crusaders or evil Jews who have committed crimes against our nation," al-Libi stated.
"Today, a new massacre is being carried out by Buddhist nationalists and communists against the Muslim population in eastern Turkestan," said al-Libi.
Islamists call Xinjiang East Turkestan. Uighurs are Muslims native to Xinjiang province, and have cultural ties to Turkic peoples in Central Asia.
"There is no way to remove injustice and oppression without a true return to their (Uighurs) religion and ... serious preparation for Jihad in the path of God the Almighty and to carry weapons in the face of those (Chinese) invaders," he said.