塞缪尔·塞尔文的小说《孤独的伦敦人》(1956)和扎迪·史密斯的小说《白牙》(2000)分别描绘了20世纪50年代加勒比移民和20世纪后30年加勒比、南亚移民在英国伦敦社会底层的生存图景。两部小说中的伦敦城市空间不仅是地理意义上的实体空间，更是权力机制的具象表达，展现出移民生活中的社会政治问题。基于文本细读，本文分析了这两部作品中伦敦城市空间描写的异同，解读这些异同所反映的不同年代、族群、性别、代际的移民境况流变。首先，伦敦荒凉的景象打破了移民对城市空间的乐观想象，无处不在的敌意使移民改善生活的期待无法实现——城市空间变成了蕴含着权力网络的异托邦，对移民的就业、住房设置限制，并在心理和话语层面不断强化边界，将移民局限在特定的城市空间和阶层中。但是，城市空间又具有流动性，伦敦的新居民们以个人或群体的形式跨越空间界限，在日常生活实践中改变城市面貌，重新定义城市空间，确立新的身份。《孤独的伦敦人》中的移民角色通过语言重新定义家庭空间，通过行走重塑街巷空间，并在小范围内实验性地打造了一个多元混杂的公共空间。这些空间实践都促进了多元文化伦敦城市面貌的形成。《白牙》中城市空间的多元文化变得更加普遍，深入人们的日常生活。不过，男性角色选择将自己限制在特定的空间中，尝试通过本质主义定义自身身份，最终遭到失败；女性移民则努力克服城市生活中的困境，在家庭和公共空间中建立人际关系、局部社会秩序和自我认知，借助城市的实体和话语空间实现了新的身份认同。

Sam Selvon’s The Lonely Londoners (1956) and Zadie Smith’s White Teeth (2000) are novels about the lives of working-class Caribbean and South-Asian immigrants in London in the 1950s and in the last quarter of the 20^th century respectively. The urban space of London in both novels is not only a geographical, material location, but also the embodiment of power relations that reveal sociopolitical issues in the diasporic experiences. By comparing the descriptions of London’s urban space in the two novels, the thesis will analyse the changes in the situations of immigrants of different times, ethnicity, gender, and generation. First, the bleak urbanscape shatters the immigrants’ optimistic imagination of London, and a pervasive hostility frustrates their expectations to improve their life standard. Second, in spite of the restrictions at both real and discursive levels that confine these immigrants to a marginal space of London, the urban space’s porous nature also allows the new Londoners to individually or communally traverse spatial limitations, reterritorialize the city, and establish new identities in their practice of everyday life. The immigrant characters in The Lonely Londoners redefine the domestic space through language, reshape the street space through flânerie, and experimentally create a hybrid public space on a small scale, all of which are spatial practices that contribute to the formation of a multicultural London. Third, the multiculturalism in the urban space in White Teeth becomes ubiquitous and permeates people’s everyday life. However, while the male characters choose to restrict themselves in certain spaces, vainly pursuing an essentialist, ethnonationalist identity, the female characters manage to forge new transcultural and interpersonal connections and reshape local social order and self-cognition in the domestic and public space, thus empowering themselves in London’s urban space.