Purpose: This study aimed to describe clearly the normal imaging features of the posterior meniscal roots (PMRs) on the magnetic resonance imaging (MRI) with a 3D proton density-weighted sequence at 3T. Materials and Methods: A total of 60 knees of 31 young asymptomatic volunteers were examined using a 3D MRI. The insertion patterns, constitution patterns, MR signals of the PMRs, and the connection between the PMRs, and between the PMRs and adjacent structures were recorded. Results: The posterior root of the medial meniscus (PRMM) had one insertion site, whereas the posterior root of the lateral meniscus (PRLM) can be divided into major and minor insertion sites. The PRMM usually consisted of multiple fiber bundles, whereas the major and minor components of the PRLM often consisted of a single fiber bundle. The PRMM typically exhibited mixed signals, whereas the PRLM usually appeared as hypointense. Some connections between the PMRs and between the PRLM and the posterior cruciate ligament were found. Conclusions: The normal imaging features of the PMRs can be complex and diverse, and certain characteristics of the PMRs were observed on 3D MRI.