Two pairs of enantiomers of biphenyl dimers, garciyndiphenyls A and B [(±)-1 and (±)-2], were isolated from Garcinia yunnanensis. These compounds represent the first example of a complex polycyclic caged skeleton of biphenyl dimers. Their structures and absolute configurations were determined through comprehensive spectroscopic analysis, X-ray crystallography, and electronic circular dichroism (ECD) calculations. Additionally, plausible biosynthetic routes for compounds 1 and 2 were proposed. Both compounds exhibited potential antimigration and anti-invasion effects in human lung cancer cells.