The core theme of the collection Love in a Fallen City is the uneasy juxtaposition of Tradition and Modernity in a Changing Society. The stories, with the exception of “The Golden Cangue,” take place during the Republic of China. It was a time when the Qing dynasty had fallen after nearly 3,000 years, and China was governed by a short-lived republic. During this Republican era, the country modernized in some ways. Women were allowed to divorce, economic mobility became more accessible to the poor and working classes, and even clothing styles transformed from traditional Chinese clothing to Western-style dress. Despite these changes, aspects of tradition endured. In this collection's novellas and short stories, Chang explores the modern changes and their refractions against the traditional mores of Chinese society.

Romantic and sexual relationships are a lens through which the novellas and short stories frequently explore the tension between tradition and modernity. For example, Liusu in “Love in a Fallen City” comes from a traditional family, and her decision to get a divorce and marry for love results in her estrangement from them. Romantic decisions related to tradition and modernity are often portrayed as having multi-generational repercussions.