The Peacock rulers of Gongmen City invent fireworks, but their son Lord Shen puts the gunpowder to evil use. Overhearing a prophecy that a "warrior of black and white" will defeat him if he continues, Shen kills all the giant pandas he can find, and is banished by his parents. Some decades later, Shen and his wolf army start to raid villages for scrap metal.
Meanwhile, Po is enjoying his new role as a Kung Fu Master alongside the Furious Five, though Master Shifu warns him he has not yet achieved inner peace. When the Wolf Boss raids the Musicians' Village, Po and the Five intercept him; however, a symbol on his armor gives Po a flashback of his mother. Po confronts Mr. Ping, and the goose reveals that baby Po arrived in a shipment of radishes outside his restaurant. When no one came forward to claim the cub, Ping adopted Po as his son.
Po and the Five are dispatched across the sea to Gongmen City next, after learning Shen has made cannons and used one to kill Master Thundering Rhino, who had been left as regent of the city. Shen and his wolves have also captured Masters Ox and Croc, taking over Gongmen City, though Shen's goat soothsayer still warns him of his probable defeat.
During the voyage to Gongmen, Master Tigress notices Po is distraught, and Po admits to her Mr. Ping is not his real dad. Upon arrival, they free Masters Ox and Croc, but the duo believes Kung Fu died with Master Rhino, and will not help.
Po and the Five deliberately surrender to Shen, who is amused by Po's naivete and prepares to kill them all without ever letting Po know he had reason for revenge. Master Mantis, who was not captured per the plan, frees the others; they destroy one of the cannons, but Po sees the same familiar symbol on Shen's plumage, which distracts him long enough for Shen to escape and destroy Gongmen Palace with his cannonade. The soothsayer tries to stop him, but Shen banishes her.
After their narrow escape, Tigress confronts Po, and Po reveals he has remembered Shen was there the day he was abandoned. Tigress sympathizes but refuses to allow Po to come with them for fear his lack of focus will get him killed. The Five leave Po behind at Gongmen Jail and proceed to Shen's cannon factory with the intent to blow it up. However, Po follows and confronts Shen, inadvertently spoiling the plan and allowing the Five to be captured. Shen lies and says Po's parents hated him, and shoots him.
Badly wounded but alive, Po floats downriver and is rescued by the soothsayer. She tells him the truth about the panda genocide, and encourages him to embrace his past. Po, finally achieving inner peace, is able to recall that his father went down fighting, while his mother hid him in a radish crate and drew off Shen's army so he could survive.
Rejuvenated, Po returns to Gongmen City, where Shen is sailing downriver with his cannons and army to start his invasion of China. Po frees the Five, and with the help of Masters Ox, Croc, and Shifu, they are able to wreck the foremost ships and prevent Shen's forces from reaching the harbor. Lord Shen fires a cannon, killing some of his own soldiers, to clear the way. The only uninjured Master after the blast, Po stands alone against Shen, using his newfound inner peace skills to deflect all the cannonballs shot at him back at Shen's fleet, destroying it. Shen attacks Po with a spear, inadvertently severing the lines holding up one of the cannons. It falls and explodes, killing Shen, while Po only just manages to jump clear.
Back at the Valley, Po is tearfully reunited with Mr. Ping, and calls him "dad" again. Meanwhile, at a secret panda village in the mountains, Po's biological father Li Shan is revealed to be still living, and senses his son is still alive.
Jack Black as Master Po
Angelina Jolie as Master Tigress
Michelle Yeoh as Soothsayer
Gary Oldman as Lord Shen
Seth Rogen as Master Mantis
Lucy Liu as Master Viper
David Cross as Master Crane
Jackie Chan as Master Monkey
James Hong as Mr. Ping
Dustin Hoffman as Master Shifu
Dennis Haysbert as Master Storming Ox
Jean-Claude Van Damme as Master Croc
Victor Garber as Master Thundering Rhino
Danny McBride as Wolf Boss
Fred Tatasciore as Li Shan
Lauren Tom as Market Sheep
Conrad Vernon as Boar
Alexander Basile as Boar #2
sequel to Kung Fu Panda (2008) and the second installment in the Kung Fu Panda franchise.