Centred around a new, condensed structure of 84 military units, the reshuffle builds on Xi's years-long efforts to modernise the PLA with greater emphasis on new capabilities including cyberspace, electronic and information warfare.
As chair of the Central Military Commission, Xi is also commander-in-chief of China's armed forces.
"This has profound and significant meaning in building a world-class military," Xi told commanders of the new units at the PLA headquarters in Beijing, according to the official Xinhua news agency report late on Tuesday.
All 84 new units are at the combined-corps level, which means commanders will hold the rank of major-general or rear-admiral, the official China Daily reported Wednesday, adding that unit members would likely be regrouped from existing forces given the Chinese military was still engaged in cutting its troops by 300,000, one of the wide-ranging military reforms introduced by Xi in late 2015.
Those reforms include establishing a joint operational command structure by 2020 and rejigging existing military regions, as well as streamlining troop numbers particularly in non-combat facing roles.
The previous seven military area commands were regrouped into five, and the four military departments - staff, politics, logistics and armaments - were reorganised into 15 agencies last year. The 84 units will come under the 15 agencies.
Retired PLA Major-General Xu Guangyu, a senior researcher at the Beijing-based China Arms Control and Disarmament Association, said the restructure represented the second major phase of Xi's reforms.
Beijing has been moving rapidly to upgrade its military hardware as it grows increasingly assertive about its sovereignty claims in the South China Sea and as it seeks to expand its military prowess overseas.
Chinese media reports have speculated that the country's second aircraft carrier - and its first built at home - will be launched on Sunday, the navy's founding anniversary.
Xi has also made rooting out deeply entrenched corruption in the military a top priority. Dozens of senior officers have been investigated and jailed.
(Reporting by Philip Wen; Editing by Michael Perry)
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