This study uses Simon de Beauvoir's The Second Sex (1949) to analyse the works that American feminist writer Margret Atwood's "The Handmaid's Tale" (1985), as well as "The Testament" (2019) From the viewpoint of feminism. Margaret Atwood, a Canadian feminist writer, is known for her work on the gender issue, particularly in her novels "The Handmaid's Tale" and "The Testaments." Feminism, defined as women fighting for their equal rights, emerged as a social movement in the United States, facing recent backlash. Atwood's stories explore the violent reaction and mysterious destruction of women's rights, while de Beauvoir focuses on the cultural and social factors behind the oppression. Atwood argues that biology is the primary cause of female oppression in a patriarchal society, and all women's roles, including sexuality, lead to their enslavement and oppression. This research uses feminist theory to examine how patriarchal society oppresses women and how women respond. Atwood presents various male characters, each with different levels of complexity and importance, which can be categorised into patterns according to their role in the story and the gender stereotype they represent. The most important characters are those who initiate the female protagonist's change and become the driving force behind the development of the narrative. The study focuses on Gileadean society, where women are treated as "Others" and run by men who hold all positions of power. Manipulation and control of women's biology and sexuality by men are major causes of their oppression. The research concludes that modern issues, including gender stereotypes and sexism, in patriarchal cultures exist in the workplace and the home, with work, position, and control characterising work. At the same time, decision-making and violence characterise the latter. Women participated in rebellion by speaking out, offering encouragement, sneaking away, and disobeying the law. The findings indicate that sexist attitudes and behaviours are common, as many people have superior-inferior ideas about sex or masculine gender, with men being seen as superior and women as less important.