Yang Zhao (楊昭) (21 February 584[1] – 30 August 606[2]), formally Crown Prince Yuande (元德太子, literally "the discerning and nurturing crown prince"), posthumously honored as Emperor Xiaocheng (孝成皇帝, literally "the filial and successful emperor") with the temple name Shizong (世宗) during the brief reign of his son Yang Tong, was a crown prince of the Chinese Sui dynasty.
His mother was Yang Guang's wife Princess Xiao, and he was their oldest son.
In 606, Yang Zhao went to Luoyang to greet his parents, and he spent several months there.
Meanwhile, because he was required to kneel before his father and had to do so repeatedly while at Luoyang, and he was severely overweight, he became ill from the fatigue, and he died in summer 606.
When his son Yang Tong later took the throne in 618 during the dynasty's disintegration, he was posthumously honored as an emperor.