Fired bricks are a hard and durable masonry material that has played a major role in the emergence of early human urban civilization. In China, fired clay bricks have been widely used as a building and flooring material since the Qin Dynasty (476-206 bc), although a few lines of evidence show that fired clay bricks might have been invented as early as 5500 years ago in eastern central China. However, these burnt clumps of clay appear not to be bricks in the strict sense, and our knowledge about the origin of fired clay bricks in China still remains fragmentary. Archaeological excavations at a Middle Neolithic cultural site in northwestern China reveal that the making of fired clay bricks began some 5000 years ago. Our findings also open a window into the process of prehistoric brickmaking in East Asia.