Introduced the preliminary knowledge on group testing and affine plane,then constructed a d-disjunct matrix on the affine plane with n order and proved some of its properties,and compared it with the d-disjunct matrix on the projective plane with n order.

In this paper, by cross ratio, on affine plane, as to conic, we probe the locus equation of intersection point of two tangent lines with intersectional angle θ, and reveal several special examples about it.

In two affine planes,if one affine plane is taken homothetic transformation or reflecting transformation at definite value,they can reach the corresponding tangential transformaation.