He has designed significant buildings in China as well. In the early 1980s, he began work on the Bank of China headquarters in Hong Kong, a project that tied together three generations; his father, Tsuyee, had been one of the bank's early managers, and Pei's collaborators on the project were two of his sons, Chien Chung (Didi) and Li Chung (Sandi), who have their own firm, Pei Partnership Architects. In keeping with the Chinese tradition of respecting elders, the Bank of China asked Tsuyee for permission to approach his son about designing the building. However, the elder Pei did not live long enough to see the bank open in 1989. The building, a stunning structure of glass and steel, was an engineering triumph. Challenged to make it resistant to typhoons, Pei abandoned the traditional column-and-beam structural model. Instead, most of the building's weight is borne by huge diago­nal trusses, which are fitted into the interior and connected to the vertical planes of the exterior. The trusses transfer the building's wind and gravity loads to its four corners, which are reinforced with composite columns. The Bank of China tower soars 72 stories and was the tallest building in Asia when it opened. A model of the bank is one of the few embellishments in Pei's New York office.

In October 2006, Pei was on hand when the Suzhou Museum, which he also designed with Didi and Sandi, opened with great fanfare in the Chinese city of Suzhou. The media made much of the Pei family's 600-year history in the ancient city, a center of art and culture known for elaborate retreats built by well-to-do families. Pei spent his childhood summers there, playing in the famed rock gardens at his family's retreat, the Garden of the Lion Forest.

In First Person Singular, he tells of how rock gardeners choose rocks, chisel them, and place them on a beach to let the tides smooth away the edges, sometimes for decades. His early exposure to the Suzhou rock gardeners, with their respect for the importance of time, had a lasting effect on him--"not just [on] my work but the way I am," he says in the film. "There is no instant gratification in creating a work of art. ... A work of art or architecture needs time [for us] to finally make a judgment as to whether it is right or not."

Pei's architectural sensibility, too, took time to develop. When he left China, he planned to study architecture at the University of Pennsylvania but was dismayed by Penn's adherence to the Beaux Arts style and left after two weeks. He says, "I wrote to MIT that I wanted to come and learn about architectural engineering. I had an adequate [math and] science background, but not art, especially Western art. So I thought that might be a better field for me to pursue."

William Emerson, dean of MIT's School of Architecture, encouraged Pei to study architecture, but Pei resisted, saying that he didn't draw well. Emerson countered that he didn't know any Chinese who couldn't draw. "The dean was wonderful," says Pei. "I owe a lot to him."