In this paper I want to compare the history and structure of the Roman and Chinese empires and in particular to point out some striking contrasts between them.. We may talk about “the Chinese and the Roman empires” and use the same word “empire” to describe them both. Are we, however, justified in so doing? The thesis of this paper is that although the Chinese and Roman empires had a number of superficial characteristics in common, they were really quite different kinds of institutions or sets of institutions, and were based on quite different sorts of society. There are two fundamental contrasts between the Roman and the Chinese empires. Firstly, the Roman empire was maritime, mercantile, urban and militaristic. It was based on the Mediterranean and the unity of the trade routes, crisscrossing the Mediterranean and spilling out into the black Sea. The Chinese empire, on the other hand, was territorial, agricultural, rural and civilian. It was based on the river valleys of the Hwang Ho and Yangtse and on the unity of agricultural techniques over this area. Secondly, the Roman empire was socially unharmonious, was torn by class conflict, and was highly unstable. The Chinese empire, on the other hand, was socially harmonious, had no irreconcilable class conflicts and was highly stable. Unless these two contrasts, of structure and stability of structure, are recognised, the use of the same word “empire” to describe both China and Rome is misleading in the extreme.