This paper defines an operation on the rational points of conic curves C_n(a,b) over the residue class ring Z_n. This operation is called addtion forces C_n(a,b) into a finite abelian group.

• 通过对Zn上圆锥曲线Cn(a；b)定义加法运算；证明了Zn上的圆锥曲线Cn(a；b)在所定义的加法运算下构成一个有限交换群.