It's very impressive that Crystal Island in Moscow and Re-Insurance Building in London because of their excellent architectural style.The geometrical modeling of these two buildings are investigated by the method of differential geometry and differential equation, which is known as two-differential in brief.The inclined straight line in Euclidean space is oriental and short-range.Similar to this orientation, loxodromic line in two-dimensional curved space is intrinsic oriental.After the differential equation of loxodromic line in revolution surface is derived from this definition, the restriction equations of those in inferior-arc revolution surface and in pseudo-sphere can obtain.Then its easy to get the coordination of all discrete points according to the corresponding analytical or numerical solutions.The three dimension geometry is modeled by the steps of connecting adjacent points, rotating array and mirror.It can be referred to modeling other similar buildings.