Quách Mạt Nhược kết hôn ba lần. Ông có 4 trai 2 gái với bà Sato Tomiko rồi cũng 4 trai 2 gái với vợ sau là Vu Lập Quân. An article published in the 2000s said that eight out of the eleven were alive, and that three have died.[6]

• Nam tử Quách Hòa Phu (郭和夫) (December 12 (or 31, according to other sources) 1917, Okayama - September 13, 1994). A chemist, he moved from Japan to Taiwan in 1946 and to mainland China in 1949. He was the founder of the Institute of Chemical Physics of the Chinese Academy of Sciences.[7]
• Nam tử Quách Bác (郭博) (sinh 1920), a renowned architect and photographer. He came to China in 1955, invited by his father, and worked in Shanghai, where he participated in the design of many of its famous modern buildings.[7] Guo Bu is also known as a photographer of Shanghai's heritage architecture;[7] an album of his photographic work has been published as a book.[8]
• Nam tử Quách Phú Sinh (郭福生).
• Nữ nhi Quách Thục Vũ (郭淑禹), giáo sư Nhật ngữ, đã qua đời.
• Nam tử Quách Trí Hoành (郭志宏).

• Nam tử Quách Hán Anh (郭汉英) (sinh 1941, Trùng Khánh). An internationally published theoretical physicist.[7]
• Nữ tử Quách Thứ Anh (郭庶英).[9] She published a book about her father.[10]
• Nam tử Quách Thế Anh (郭世英) (1942 - April 22, 1968). In 1962, while a philosophy student at Beijing University, he created an "underground" "X Poetry Society". In the summer of 1963 the society was exposed and deemed subversive. Guo Shiying was sentenced to re-education through labor. While working at a farm in Henan province, he developed interest in agriculture. Returning to Beijing in 1965, he enrolled at Beijing Agricultural University. In 1968, kidnapped by Red Guards and "tried" by their "court" for his poetry-society activity years before he jumped out of the window of the third-floor room where he was held and died at the age of 26. His father in his later writing expressed regret for encouraging his son to return to Beijing from the farm, thinking that it indirectly led to his death.[11]
• Nam tử Quách Dân Anh (郭民英), (November 1943, Trùng Khánh - April 12, 1967). His death is described as an unexpected suicide.[11]
• Ái nữ Quách Bình Anh (郭平英)
• Nam tử Quách Kiến Anh (郭建英) (sinh 1953).