In China, Itier documented the conclusion of the Treaty of Whampoa and took a number of daguerreotypes of Chinese people and scenery in the Guangdong region.
Although the daguerreotype reportedly reached China in the later stages of the First Opium War, Itier's daguerreotypes are the earliest preserved photographs of China.
Upon his return to France, Itier wrote an extensive travelogue of his journey to China.