The universal transition of Lyapunov exponents between conservative li
mit and dissipative limit of nonlinear dynamical system is studied. It
is discovered numerically and proved analytically that for homogeneou
s dissipative two-dimensional maps, along the equal dissipation line i
n parameter space, the Lyapunov exponents of attractor orbits possess
a plateau structure and strict symmetry about its plateau value. The r
atios between the plateau width and the stable window width of period
1-4 orbits for Henon map are calculated. The result shows that the pla
teau structure of Lyapunov exponents remains invariant for the attract
or orbits belonging to a period doubling bifurcation sequence. This fa
ct reveals a new universal transition behavior between order and chaos
when the dissipation of the dynamical system is weakened to zero.