Manchu is one of the few minorities in the history of China which created texts. It created a 32 Fonts of Manchu seal characters and used 10 fonts in making Royal Seals in Qing Dynasty, in combiniation with Han seal characters. Such combination marks the greatest development in the history of making royal seals, but still there are some errors in matching perfectly the Manchu and Han seal charaters in making royal seals, and such errors can ben found even in Eulogy of Mukden by Emperor Qianlong and the inscriptions on top part of some steles. This paper identifies the errors in sampled royal seals, studies the causes, and suggest the corrections. This reserch is a contribution to a comprehensive, accurate and objective evaluation to the historical and cultural significance of Manchu seal characters, and it also benefits the studies on Manchu seal characters and Royal Seals in Qing Dynasty, as well as the further development of ethnic art and culture in contemporary China. The researcher calls the academic community to pay attention to the profound significance of Manchu seal characters, and propose earnestly the objective, rigorous and scientific study method in Manchu language studies.