Head coach Allen Clarke and team captain Peter O'Mahony guided last season's Ireland Under-20s to an eighth place finish at the 2009 tournament, with wins Argentina and Uruguay and an impressive display against eventual champions New Zealand along the way.
IRB Chairman Bernard Lapasset said: "The IRB Junior World Championship is essential for the development of elite international players and officials and I have no doubt the UAR will host a colourful, exciting and passionate event."
The new format sees 12 teams in three pools for the 2010 IRB Junior World Championship:
Pool A: New Zealand (holders), Wales, Samoa and Fiji
Pool B: England, France, Ireland and Argentina
Pool C: South Africa, Australia, Scotland and Tonga
This will be the third successive Junior World Championship that Ireland have faced Argentina in the pool stages, with the Argentinians winning 17-9 at the inaugural tournament in 2008 in Wales and the Irish gaining some revenge with a 16-9 victory in Japan in June.
Clarke's charges will clash with France on Saturday, June 5 - the opening day of the tournament - with pool games against England and Argentina to follow on Wednesday, June 9 and Sunday, June 13 respectively.
Ireland's three pool games will be played in Rosario.
IRB Tournaments Manager Philippe Bourdarias said: "We are looking forward to an intense festival feel to the Junior World Championships in Argentina with 30 matches concentrated in one region.
"The reduction to 12 teams will create a more competitive tournament from round one."
UAR President Porfirio Carreras added: "We are proud to be hosting the IRB JWC 2010 in a region of Argentina rich in rugby heritage.
"We look forward to welcoming the teams here next year and using the tournament to galvanise interest in the sport amongst our young people."
The 2010 tournament's opening matches include hosts Argentina taking on 2009 runners-up England in Rosario and hholders New Zealand starting their title defence against Fiji in Paraná.
The IRB Junior World Championship will provide a further boost to the ongoing development of rugby in South America, in particular the UAR's High Performance strategy which is funded through the IRB's Strategic Investment Programme resulting in an annual investment of US$2 million.
Click here for the full match schedule.