Objective To explore the knowledge and needs of fertility preservation in reproductive-aged male patients with cancer. Methods A cross-sectional survey was conducted in 322 reproductive aged male patients with cancer regarding their knowledge and needs of fertility preservation. Results The participants scored (3.5±0.7) points in fertility preservation knowledge; 77.71% rea-lized that cancer treatment could impair fertility, 63.86% didn′t know how to, and 80.72% didn′t know where to, preserve fertility.Only 10.54% had resorted to a sperm bank to preserve fertility before cancer treatment, and 68.67% wanted to preserve fertility during cancer treatment.Multivariate logistic regression analysis showed that, family monthly income, and ages influenced the participants′ knowledge of fertility preservation （P＜0.05 for both）; ages and having a child or not influenced the participants′ （P＜0.05 for both）. Conclusion Male cancer patients of reproductive age had limited knowledge of fertility preservation, and the majority didn′t make fertility preservation arrangements before cancer treatment.However, a large proportion of them wished to preserve fertility during cancer treatment.Young patients and those who had family monthly income ≥8 000 Yuan tended to be more knowledgeable of fertility preservation; young and child-free patients had the needs of fertility preservation during cancer treatment.Medical staff should fully discuss with patients about fertility preservation issues, make a full assessment of patients′ understanding of fertility preservation information , and arrange practical fertility preservation measures and guidance for them.