Born in Pascani, Marius  studied  at  the Prince Claus Conservatoire - Hanze University - Groningen (Paesi Bassi), under the guidance of Prof. Sorin Orcinschi  and got the highest marks  in 2013 (Master Diploma); at "Luigi Boccherini Conservatoire  in Lucca (Italy) with the teacher Gabriele Ragghianti and he got  the highest marks cum laude in 2010 (II level Diploma)  and in the same Conservatoire he has studied with professor Sergio Grazzini and got again the highest marks in 2007 (Bachelor Diploma).

He was invited to participate like soloist, as member of chamber music ensembles and as orchestral  player  at famous  international festivals: Peter de Grote Festival in Groningen (Netherlands), Ravenna Festival (Italy), Ravello Festival (Italy), "Mito Settembre Musica " Milan (Italy), Salzburger Festspiele (Austria), Bahrein  Festival,  Abu Dhabi Festival (UAE) and others festival.

He is currently performing an intense chamber activity in collaboration with  musicians as: Marcel Brouns, Ilona Sie Dhian, Emmy Verheij, Aaron Berofsky, Harro Uijsenaars, Victoria Dmitrieva, Dunja Roboti and many others.

He played under many famous conductors like: M° Riccardo Muti, M° Edward Gardner, M° Michael Schønwandt,  M° Alessandro de Marchi,  M° Duncan Ward, M° Charles Dutoit, M° Bertrand de Billy, M° Mischa Damev, M° Rafael Payare,  M° Dennis Russel Davies, M° Wayne Marshall, M° Pinchas Zukerman, M° Daniel Oren, M° Keri Lynn Wilson and many others important conductors.

 He plays with many orchestras as  double bass player: Royal Concertgebouw Orchestra of Amsterdam, ​Radio Chamber Philharmonic Orchestra of Amsterdam, Luigi Cherubini Orchestra  of Piacenza  under the conducting of  Riccardo Muti– Italy,   “Malta Philharmonic Orchestra” of  Malta,  Simphony Orchestra of India  performing a lyric and symphonic repertoire.

Marius performs in numerous concerts as member of orchestras in different important Concert Halls and theaters in all the world like: ConcertGebouw  Theatre of Amsterdam (Netherlands), Royal Theatre of Madrid (Spain), Concert Hall of Oviedo (Spain), Concert Hall Haus fur Mozart in Salisburg (Austria), “Musikvereign” Theatre of  Wien (Austria), Stefaniensaal of Graz (Austria), Felsenreitschule  in Salisburg (Austria), Royal Theatre of Namur (Belgium), Concet Hall of Gent (Belgium), Palace of Congress in  Lugano (Switzerland), “Mediteranean  Conference Centre” of Valletta (Malta), Colon Theatre of  Buonos Aires (Argentina), Huafa  Concert Hall of Zhuhai (Cina), Jamshed Bhabha Theatre of Mumbai (India), Royal Opera House of  Muscat (Oman),   National  Theatre of Bahrain, Concert Hall of Abu Dhabi, (UAE) “Uhuru Park” in Nairobi (Kenya),  Concert Hall of Milan (Italy), Alighieri Theatre of  Ravenna (Italy), Parco della musica of Rome (Italy), Theatre of Piacenza (Italy), Verdi Theatre of Pisa (Italy), Paganini Concert Hall of Parma (Italy), Ponchielli Theatre of Cremona (Italy), Giglio Theatre of Lucca (Italy), Theatre of Ferrara (Italy),  and many other important theaters.

Starting with 2008 Marius teaches at the Luigi Boccherini Conservatoire  in Lucca  and  Nicola Sala Conservatoire in Benevento.

Marius Cojocariu plays an Italian Anonym double bass model “pear” from 800.