摘要
We study the structure of solutions to the interface problems for second order quasi-linear elliptic partial differential equations in two dimensional space.We prove that each weak solution can be decomposed into two parts near singular points,a finite sum of functions in the form of cr^α long^m γψ（θ） and a regular one w .The coefficients c and the C^1,α norm of w depend on the H^1-norm and the C^0,α-norm of the solution ,and the equation only.
