Alzheimer's disease (AD) is the leading cause of dementia. With aging societies, the prevalence of AD is increasing dramatically worldwide. The onset of AD is often not identified, and currently no available treatments are capable of stopping the disease process and its effect on cognitive decline. Thus, well-validated biomarkers of the preclinical stages of AD are needed. Alzheimer-associated neuronal thread protein (AD7c-NTP) is a member of the neuronal thread protein family and has a molecular weight of approximately 41 kD. AD7c-NTP has been identified as a biomarker for its specifically elevated levels in putative brain domains, cerebrospinal fluid (CSF), and the urine of AD and mild cognitive impairment (MCI) patients. Since the urine test is non-invasive, easy to perform, and patients accept it more easily than other methods, the urinary AD7c-NTP concentration has been recommended as a practical diagnostic tool for diagnosing AD and MCI. AD7c-NTP has undergone nearly 25 years of research course from its initial discovery to pathological verification, multi-center clinical evaluation, improvement of detection methods, epidemiological investigation, and combined application with other biomarkers. However, as a fluid biomarker, AD7c-NTP can be detected in urine instead of the traditional biomarker sources-CSF or blood, which has made the use of AD7c-NTP as a biomarker controversial. In this article, we review the research course of AD7c-NTP and suggest directions for future research.