The purpose of this paper is to investigate into the meaning of the New Brutalism sensed in the late church buildings of the Swedish architect Sigurd Lewerentz (1885-1975). St Mark's (1956-64) and St Peter's (1962-66) churches, his grand finale designs, have a unique architectural vocabulary of rough brickwork. The brick treatment is the basis on which Reyner Banham (1966) discussed him concerning the New Brutalism, and the point that this research focuses on. This paper explores the brutalist character of the buildings from two aspects - interpretational level of individual buildings and historical level of a broader view. First, the character of two churches could be interpreted with the phrase of 'play between brutality and sacredness'. The rough surface of brick and mortar in the buildings symbolises brutality and the vault of their chapels' ceiling sacredness. And the two characteristics meet and play on the rough vault surface. Second, in the historical point of view, this paper argues that the buildings made a giant leap for Swedish modern architecture, which had been at a deadlock owing to the compromising attitude of the New Empiricism since 1940s. And the Swedish New Empiricism (or the New Humanism), spread to Britain as "Welfare State architecture" after World War II, brought about reaction of the young British architects such as the Smithsons and became the background that made the new brutalist mood. However, considering that the term of the New Brutalism was first used in Sweden by Hans Asplund, Lewerentz's brutalist late churches - which seemingly had nothing to do with the British nor the Corbusian lineage - are also meaningful in that they confirmed the tendency in its homeland. In conclusion, this paper argues that St Mark's and St Peter's churches with the brutalist characteristics should be regarded as crucial buildings not only in Lewerentz's personal career but also in Swedish and international architectural history.