Taiwan is the first country in Asia to recognize the legal rights of same-sex couples to get married. Although same-sex marriage has been legal in Taiwan since May 2019, the same-sex marriage family was not allowed to adopt child legally; only stepchild adoption was permitted. This is still a very controversial issue, so this study intended to understand the views of Taiwanese college students, whose voices should be heard and whose opinions should be valued by legislators. To investigate this issue, a questionnaire was constructed, and 440 objects were collected. The questionnaire regarding attitudes toward same-sex marriage adoption consisted of three dimensions: “Worry and against”, “Idea Recognition” and “Action Support”. Each dimension has good reliability. The internal consistent coefficients (Cronbach’s α) were 0.86, 0.93, and 0.94. The responses reveal that college students in Taiwan have a relatively positive attitude towards same-sex marriage adoption, and college students who are biologically female, non-heterosexual, non-Christian, major in social work, and are acquainted with the LGBT community have more positive attitudes. College students’ same-sex marriage and adoption attitudes can be predicted by biological sex, sexual orientation, religion, grade, whether they major in social work, have contact experience with the LGBT community, contact experience with adoption, and same-sex parenting concepts. The same-sex parenting concept is the most important predictor variable, which means that the judgment about whether same-sex marriage couples can bear the responsibility of raising children is the most critical factor affecting the attitude of same-sex marriage adoption.