Abstract: This article conducted a comparative analysis of the background and fundamental differences between the 505(b)(2) drug and modified new drug, with a focus on successful case studies of 505(b)(2) drugs, discussing clinical requirements and development trends. Based on the national conditions of our country, the project initiation considerations and examples of improved new drugs were carried out from the perspective of preparations. Additionally, the causes of improvement failures and relevant cases were analyzed and discussed, providing critical insights to advance the development of modified new drug in China.