One of the most fundamental questions in nuclear physics is how nuclear physics itself emerges from the underlying theory, quantum chromodynamics (QCD), and the determination of baryon forces from QCD plays a crucial role to answer this question. In this talk, I review the first-principles lattice QCD calculation of baryon forces as well as general hadron-hadron interactions. I introduce a novel theoretical framework, HAL QCD method, and present the latest lattice QCD results, in particular, those obtained near the physical point. The physical implications for exotic dibaryons, equation of state of high dense matter and the structure of neutron stars are also discussed and future prospects will be given.