Worcester wing sensation Miles Benjamin, whose brace stunned Australia in the last game, is named while the other changes see Alex Tait come in at full-back for Noah Cato, who switches to the other wing, and Ben Thomas in the pack.
England are unbeaten in eight games at Under 20 level this season, scoring 38 tries in total, after completing a Six Nations Grand Slam and beating Fiji (41-17), Canada (60-18) and Australia at the Junior World Championship.
New Zealand take on hosts Wales in the other semi-final at Swansea (7pm) and both games are being shown live on BBC Wales.
England Under 20 team
15 Alex Tait (Newcastle Falcons)
14 Noah Cato (Saracens)
13 Luke Eves (Bristol Rugby)
12 Jordan Turner-Hall (Harlequins)
11 Miles Benjamin (Worcester Warriors)
10 Alex Goode (Saracens)
9 Joe Simpson (London Wasps)
1 Nathan Catt (Bath Rugby)
2 Joe Gray (Northampton Saints)
3 Alex Corbisiero (London Irish)
4 Ben Thomas (Saracens)
5 Gregor Gillanders (Leicester Tigers)
6 Matthew Cox (Worcester Warriors)
7 Calum Clark (Leeds Carnegie)
8 Hugo Ellis (London Wasps, captain)
16 Scott Freer (Leeds Carnegie)
17 Billy Moss (Bath Rugby)
18 Scott Hobson (Cornish Pirates)
19 Jon Fisher (London Irish)
20 Ben Youngs (Leicester Tigers)
21 Rob Miller (Newcastle Falcons)
22 Mark Odejobi (London Wasps)
England play South Africa on Wednesday, June 18 (9.10pm) in the semi finals of the IRB Junior World Championship. You can watch them live on BBC2 Wales while Digital viewers in England can see the game behind the red button, and Satellite viewers should go to Sky Channel 991 or watch on Eurosport 2.