Purpose: The advances of early cancer diagnoses and treatment methods allow many adolescent and young adult-aged cancer patients to live long lives after having cancer. There is a rising concern regarding cancer treatment-induced reproductive toxicities and infertility. Oncologists are the first line of medical professionals interacting with cancer patients and playing essential roles in oncofertility practice. This study aimed to assess the oncofertility knowledge, attitude, and practice of oncologists in China. Methods: We created an online questionnaire survey to examine 927 Chinese oncologists’ demographics, knowledge, attitude, experience, and practice regarding young female cancer patients’ infertility risk and fertility preservation. Results: Results showed that there is an inadequate oncofertility knowledge among surveyed oncologists, which was affected by oncologists’ demographic background of education level, clinical title, and working experience. The majority of surveyed oncologists (84.8%–88.7%) held a positive attitude on young female cancer patients’ infertility risk and their fertility preservation demand, but their attitude was impacted by marriage status and patients risk of cancer recurrence. Only 11.8% of surveyed oncologists often referred their patients for fertility preservation, while 66.3% and 21.9% of them have referred once or never, respectively. The oncologists’ oncofertility practice was not correlated with their demographic background but was significantly influenced by their oncofertility knowledge and attitude. Conclusion: Our study demonstrates that there is an urgent unmet need to improve oncologists’ oncofertility knowledge, attitude, and practice in China as well as remove the communication barrier between oncologists and fertility specialists. Purpose: The advances of early cancer diagnoses and treatment methods allow many adolescent and young adult-aged cancer patients to live long lives after having cancer. There is a rising concern regarding cancer treatment-induced reproductive toxicities and infertility. Oncologists are the first line of medical professionals interacting with cancer patients and playing essential roles in oncofertility practice. This study aimed to assess the oncofertility knowledge, attitude, and practice of oncologists in China. Methods: We created an online questionnaire survey to examine 927 Chinese oncologists' demographics, knowledge, attitude, experience, and practice regarding young female cancer patients' infertility risk and fertility preservation. Results: Results showed that there is an inadequate oncofertility knowledge among surveyed oncologists, which was affected by oncologists' demographic background of education level, clinical title, and working experience. The majority of surveyed oncologists (84.8%-88.7%) held a positive attitude on young female cancer patients' infertility risk and their fertility preservation demand, but their attitude was impacted by marriage status and patients risk of cancer recurrence. Only 11.8% of surveyed oncologists often referred their patients for fertility preservation, while 66.3% and 21.9% of them have referred once or never, respectively. The oncologists' oncofertility practice was not correlated with their demographic background but was significantly influenced by their oncofertility knowledge and attitude. Conclusion: Our study demonstrates that there is an urgent unmet need to improve oncologists' oncofertility knowledge, attitude, and practice in China as well as remove the communication barrier between oncologists and fertility specialists.