The Brazilian centre-half is a reported target of Spanish giants Barcelona, who are looking to strengthen their defensive line following the departure of veteran captain Carles Puyol. PSG brought in David Luiz from Chelsea earlier this month, a move that has increased speculation linking Marquinhos with the exit door.
When asked about Marquinhos, Blanc said to Radio Monte Carlo: "He will certainly stay. I'm interested in keeping the same group we had this year."
Marquinhos joined the Ligue 1 champions last summer from Roma in a €31million transfer deal. The 20-year-old made just 17 league starts for PSG and is under contract with the Parisian club until June 2018.
Blanc, whose side won the Ligue 1 title and the Coupe de Ligue in the 2013-14 campaign, has confirmed PSG will make at least one more signing: "We have already acquired David Luiz," the 48-year-old said." At least one or two more players will arrive this summer."