Dynamic properties of peaty soils from Kunming basin are investigated through a series of undrained cyclic triaxial testing. The effects of confining pressure

consolidation ratio

and loading frequency on the maximal shear modulus G

max

dynamic shear modulus G

d

normalized shear modulus G

d

/G

max

and damping ratio λ are analyzed. Test results indicate that G

max

of Kunming peaty soil increases linearly with increasing confining pressure and consolidation ratio. G

d

decreases as well as λ increases with increasing sh

ear strain amplitudedg. When shear strain amplitude is small

G

d

and λ change slightly. As shear strain increases to a certain degree

they change rapidly. G

d

/G

max

is weakly influenced by confining pressure

consolidation ratio and loading frequency

the damping behavior is significantly influenced by confining pressure and loading frequency and is weakly influenced by consolidation ratio. A regression model considering confining pressure and consolidation ratio is developed. Meanwhile

the relations are provided for G

d

/G

max

and λ versusdg by using the Davidenkov model. The results show that the fitting models can describe the variation for peaty soil well. The difference of dynamic shear modulus and damping ratio characteristics for peaty soils in other regions and different soils is analyzed as well.