Abstract：To understand the spin structure of a nucleon is a fundamental goal of nuclear science. After half a century of investigations, our knowledge of the nucleon spin structure has made impressive progress. However, our current understanding is basically one-dimensional. Meanwhile, the past decade has witnessed tremendous experimental achievements, which led to fascinating new insights into the 3-D structure of the nucleon through semi-inclusive deep inelastic scattering processes (SIDIS). In this talk, I will firstly give a brief introduction on perspectives for the spin structure study to help people to get a feeling on where we are for the one-dimensional picture and why we need to move to 3D studies (TMDs and GPDs). Then I will discuss some results and future efforts at JLab (6 GeV and 12 GeV) and COMPASS (CERN) for the TMDs study. The contributions from a future Electron-Ion Collider (EIC) on the study of TMDs will also be discussed.