LIVE UPDATES: SA v NZ
Du Plessis missed South Africa's five-run defeat in their opening match against Sri Lanka on Saturday due to a hamstring injury.
He replaces batsman Farhaan Behardien in Monday's line-up.
New Zealand made no change in the side which won their first match against England via Duckworth-Lewis method on Saturday.
Sri Lanka meet the Netherlands at the same venue later Monday. England is the fifth team in the group.
Title-holders the West Indies, India, Pakistan, Australia and Bangladesh form Group Two.
The top two teams from each of the group will qualify for the semi-finals. The final will be played in Dhaka on April 6.
Teams:South Africa: Hashim Amla, Quinton de Kock, AB de Villiers, JP Duminy, Faf Du Plessis(captain), David Miller, Albie Morkel, Dale Steyn, Morne Morkel, Lonwabo Tsotsobe, Imran Tahir.
New Zealand: Martin Guptill, Kane Williamson, Brendon McCullum(captain), Ross Taylor, Colin Munro, Corey Anderson, Luke Ronchi, Nathan McCullum, Tim Southee, Kyle Mills, Mitchell McClenaghan.