The Venezuelan, who impressed on-loan at Newcastle last season, is reunited with former Magpies boss Rafa Benitez.
The 29-year-old departs The Hawthorns after four years for an undisclosed fee but it's believed to be near his £16.5million release clause.
Rondon issued a statement saying: "I also feel very grateful to WBA for the affection from every single Baggie right from day one and for the opportunity the club gave me by bringing me to English football."
He had just one year remaining on his contract, and had no intention of returning to Albion to play in the Championship, forcing the Baggies to cash in.
Wolves, Newcastle and West Ham had all expressed an interest in Rondon this summer, but no English club got near his release clause.
Selling him to China represents the best deal for Albion, and now allows them to bring in players.
The Baggies are expected to complete an £8m deal for Cardiff City striker Kenneth Zohore today and are also closing in on Rotherham defender Semi Ajayi.
It's understood the Baggies have already had a bid for the versatile Millers player.
Rondon's exit comes as no surprise to the Baggies, with Albion's technical director Luke Dowling previously confirming that the striker would be departing.
“We’re quite happy to say that we will sell Salomon," said Dowling in June.
“We don’t want a player that’s had a season like that staying around with us and walking away on a Bosman."
The striker leaves having made 120 appearances in Albion colours, scoring 28 goals.