Post office to China refers to the process of shipping items from a post office in the United States to China. USPS offers various international shipping options to China, including First-Class Mail International, Priority Mail International, and Priority Mail Express International. Delivery times vary based on the service chosen, with First-Class Mail being the most affordable but slower option, and Priority Mail Express offering faster delivery. USPS provides tracking services for most international shipments to China, allowing customers to monitor their packages as they move through the postal system.