The 27-year-old, who is preparing to represent Brazil at the FIFA World Cup, looks set to seal a switch to the Ligue 1 champions after a deal was announced on Friday.
And the defender, who moved to Stamford Bridge from Benfica in 2011 and won the FA Cup, UEFA Champions League and Europa League with Chelsea, revealed his mixed emotions ahead of the transfer.
"Thanks Chelsea for the three and half years of great partnership," he wrote on his Facebook page.
"I've made good friends, won many titles and those memories will last with me for ever.
"I'd like to thank my team-mates, all staff and all supporters (my geezers).
"I'm leaving with great sadness but at the same time excited for the new challenge that lies ahead in this great club in a city that have always enchanted me.
"It's a new stage, new challenge and together we will go even further."
PSG are reportedly set to pay €50 million for Luiz's services, a world-record fee for a defender.
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