Hampstead Garden Suburb (HGS), north-west of London, was planned in 1906. It was proposed by Dame Henrietta Barnett (1851-1936), a wife of a Canon. Helping the poor for many decades, she proposed a well-planned suburb with large open space and beautiful landscape and architecture “to include all classes”1. HGS is thus the world’s first suburb embodying socialism and embracing all classes. It is different from the ordinary suburbs of the time, which were planned by developers, have highly diversified appearances, and only rich people can afford to buy. Barnett and HGS have been studied by various scholars, but almost no research explores the exact core value behind HGS and how it was realized. Therefore, this paper focuses on this. I use qualitative methods to analyse Barnett’s own writings. I find that 1. morality and aesthetics are the core value 2. morality was emphasized during the initial stages of HGS’s establishment and aesthetics the later stages. I will elucidate the relevant time sequence 3. any constructions to enhance beauty and aesthetics are actually built for their moral value. So aesthetics is another way to express morality. Overall, this paper hopes to inspire readers by highlighting the morality and aesthetics behind a suburb, an aspect often neglected by Urban History and Town Planning. Moreover, though falling into the category of History of Architecture, this paper does not focus on the discipline’s traditional propositions such as form and style, but on thinking and ideas, and is therefore a unique contribution.