Abstract: A numerical method is put forward to describe the effect of LEO's orbital errors on the inverted parameters of terrestrial atmosphere. Quantitative results are presented based on an occultation event on Oct.11, 1995. LEO's orbital errors show some features:temperature inversion precision at higher altitudes depends more on LEO's positional accuracy than that at lower altitudes in radial and transverse components, while it holds true the other other round in the normal component. Pressure inversion precision at higher altitudes depends less on LEO's positional accuracy than that at lower altitudes in normal and transverse components, while it holds true the other way round in the radial component. Inversion parameters at higher altitude are more insensitive to the velocity bias than that at lower altitude.