Shah will again meet the Chief Minister at his official residence at dinner, when crucial discussion on 2019 general election seat sharing between the allies was expected.
A team of BJP leaders, including Union Ministers from Bihar, Deputy Chief Minister Sushil Kumar Modi earlier thronged the Patna airport with garlands to welcome Shah.
This is Shah's first visit after Nitish Kumar's JD-U joined the National Democratic Alliance in July 2017 after dumping the Rashtriya Janata Dal and Congress of the Grand Alliance.
Unprecedented security arrangements have been made for Shah's visit. The state capital has been turned into a fortress with thousands of security personnel deployed and traffic diversions in place.
The entire city has been flooded with colourful hoardings, banners, high rise gates and posters highlighting the achievements of four years of the Narendra Modi government at the Centre.
Shah will be holding series of meetings and discussions with the party leaders and workers on preparations leading up to the 2019 general elections.
He will interact with 10,000 ground level party workers, who head the booths in the state. Besides, he will also meet the party's social media activists to discuss the digital campaign, a BJP leader said.