The YSRCP Legislature Party will meet at the party office at 11 a.m. According to party sources, it will pass a resolution unanimously electing Reddy as its leader.
YSRCP, which stormed to power bagging 151 seats in the 175-member Assembly, will later submit a resolution to Governor E.S.L. Narasimhan to formally stake claim to form the government in the state.
Jagan, as the YSRCP leader is popularly known among his supporters, has already announced that he will take oath as the chief minister on May 30 in Vijayawada.
Officials started making arrangements for the swearing-in ceremony, which is likely to be attended by Telangana Chief Minister K. Chandrashekhar Rao and leaders of some other regional parties, at the city's Indira Gandhi Municipal Stadium.
A large number of YSRCP workers from across the state are expected to attend the event, which is likely to take place between 11.40 a.m. and 12 noon.
Vijayawada Police Commissioner Dwarka Tirumala Rao met Jagan on Friday to discuss the arrangements, though it was not clear if he alone will take oath or so some legislators would also be sworn-in with him as ministers.
Meanwhile, a day after YSRCP's landslide victory, aspirants of ministerial berths and top bureaucrats made a beeline at his residence at Tadepalli in state capital region Amaravati.
Senior party leaders and legislators, including those who worked as ministers in the Cabinets of Jagan's father Y.S. Rajasekhara Reddy between 2004 and 2009, were among the aspirants who called on the party leader.
The YSRCP chief began the day by offering prayers at Tirupati's Balaji temple. Temple Executive Officer Anil Kumar Singhal, who accompanied the priests, offered prasadam to Jagan and his family members.
Leaders and workers from various parts of the state continued to descend on Tadepalli in processions to celebrate the party's massive victory.
The road leading to Jagan's home in Tadepalli village on the banks of Krishna river was barricaded on both sides.
Top Indian Administrative Service (IAS) and Indian Police Service (IPS) officials too made a beeline at Jagan's house to congratulate him. Those who called on the leader, included Director General of Police (DGP) R.P. Thakur.
Meanwhile, the General Administration Department (GAD) has readied six-vehicle convoy for the new chief minister.
( With inputs from IANS )