The new advance and trend in the ecological complexity studies,its background,methodology and theory are briefly introduced.

Based on the ecological complexity theory,the paper analyses the wetland characteristics of Hutuo river from Gangnan reservoir to Huangbizhuang reservoir,and constructs the evaluation system and the standards of the health ranks to diagnose and evaluate the wetland ecosystem health from four aspects: structure,state,function and coordination with the fuzz.

From the angle of epistemology and methodology,analytical theories of exergy and emergy is new methods for measuring ecological complexity.

The importance of carrying out study of system complexity and complicated management on studying the complexity of forest eco_system and its management was described.

The dynamic complexity of "super-coupling-in-trinisic randomness" of modern social economy was studied which includes: super-autonomous social turbulence; non-well-illuminated situation perspective; background fluctuation of indeterminate extent; forecast reliability of variable probability; integration of intellect, emotion and benefit-men and things; multidimensional technol.

Then we present two of our original works in this aspect, one on the state complexity of transforming ω-automata, and the other on the (generalized) star height problem.