Scotland coach Frank Hadden and Scotland A head coach Steve Bates liaised on the selection of both squads. Scotland A also announced their squad today for the Barclays Churchill Cup in North America next month.
The Scotland A squad, which will be led by Edinburgh Gunners' scrum-half Rory Lawson, includes 15 uncapped players in the 28-strong group.
The Barbarians visit to Murrayfield on Wednesday 31 May represents the first anniversary of Hadden taking over the coaching reins of the national team.
Hadden said today: "When I look back to last year I recall just how enthusiastic the players were to perform for their country at the end of a long, draining season.
"This season has again been challenging, physically and mentally for the players, but through their hard work and utter determination, they have gained some tremendous reward culminating in Scotland's best ever finish in the RBS 6 Nations Championship.
"Over the last few weeks I have spoken at many club dinners around the country and the resounding message that has come back from those gatherings is just how much the country has enjoyed the progress that the team have made.
"Supporters have asked me to take back the message to the players and coaches of how much our results have meant to them this season and how our displays have cheered up everyone.
"That enthusiasm is infectious and what's been really heartening for me this week at our training camp is just how much the players are looking forward to building on what has been achieved.
"Our matches against the Barbarians and South Africa and Scotland's A games against England and Canada are important in their own right but they also give the players the chance to stake a claim for the 2007 Rugby World Cup. The selection of both squads reflects the view held by all the coaches that we must give the players the best opportunity to show what they can do."
Hadden is also taking 22-year-old uncapped Edinburgh Gunners centre Rob Dewey to South Africa. He explained: "Rob is not yet fit to play but I'm keen to have him involved in certain training drills as but for two shoulder injuries he sustained this past season he would have been challenging for a place in the squad."
Bates has named Rory Lawson as his captain. Lawson, who has captained Edinburgh Gunners this season, including to a notable away victory against Cardiff Blues, also led his club side, Heriot's, winning the BT Cup in 2003.
On his chosen captain, Bates said: "Rory has a buoyant and positive influence on the squad. He is in a good position on the field to control the game and is an inspirational character off the field."
Scotland A will play England A and Canada in the pool stages of the tournament which culminates at the Commonwealth Stadium in Edmonton for the finals.
Bates said: "I've been impressed with the attitude of the players during this three-day training camp. They are all very much looking forward to touring and have been very positive and optimistic about our pool games.
"We don't have a lot of preparation time but the guys are upbeat and positive which has helped our progress."
Scotland squad
Backs - Mike Blair (Edinburgh Gunners), Marcus Di Rollo (Edinburgh Gunners), Andrew Henderson (Glasgow Warriors), Sean Lamont (Northampton Saints), Ben MacDougall (Border Reivers), Dan Parks (Glasgow Warriors), Chris Paterson (Edinburgh Gunners), Sam Pinder (Glasgow Warriors), Gordon Ross (Leeds Tykes), Hugo Southwell (Edinburgh Gunners), Simon Webster (Edinburgh Gunners)
Forwards - Kelly Brown (Border Reivers), Bruce Douglas (Border Reivers), Dougie Hall (Edinburgh Gunners), Nathan Hines (Perpignan), Allister Hogg (Edinburgh Gunners), Alastair Kellock (Edinburgh Gunners), Gavin Kerr (Leeds Tykes), Scott Lawson (Glasgow Warriors), Donnie Macfadyen (Glasgow Warriors), Scott MacLeod (Border Reivers), Scott Murray (Edinburgh Gunners), Jon Petrie (Glasgow Warriors), Craig Smith (Edinburgh Gunners), Jason White (Sale Sharks) CAPTAIN
Travelling with the squad: Rob Dewey (Edinburgh Gunners)
Head coach - Frank Hadden; Coaches - George Graham and Alan Tait
Scotland A squad
Backs: Simon Danielli (Border Reivers), Nick De Luca (Edinburgh Gunners), Matt Dey (Edinburgh Gunners), Phil Godman (Edinburgh Gunners), Colin Gregor (Glasgow Warriors), Rory Lamont (Glasgow Warriors), Rory Lawson (Edinburgh Gunners) CAPTAIN, Brendan McKerchar (Border Reivers), Calum MacRae (Border Reivers), Stuart Moffat (Border Reivers), Graeme Morrison (Glasgow Warriors), Nikki Walker (Border Reivers)
Forwards: Ross Beattie (Northampton Saints), David Callam (Edinburgh Gunners), Alasdair Dickinson (Edinburgh Gunners), Jon Dunbar (Leeds Tykes), Scott Gray (Border Reivers), Andrew Hall (Newport-Gwent Dragons), Craig Hamilton (Glasgow Warriors), Allan Jacobsen (Edinburgh Gunners), Andrew Kelly (Edinburgh Gunners), Nick Lloyd (Saracens), Andy Miller (Border Reivers), Colin Noon (Biarritz), Mark Rennie (Lyon), Alasdair Strokosch (Edinburgh Gunners), Fergus Thomson (Glasgow Warriors), Andrew Wilson (Glasgow Warriors)
Head coach - Steve Bates; Coach - Shade Munro
Not considered due to injury: Graeme Beveridge (Glasgow Warriors), Simon Cross (Edinburgh Gunners), Chris Cusiter and Ross Ford (both Border Reivers), Robbie Kydd (Northampton Saints), Euan Murray (Glasgow Warriors) and Simon Taylor (Edinburgh Gunners)