As a special surface texture evaluation method, motif has received much attention since it was adopted as an ISO standard which is ISO12085 1996. However, like many other evaluation methods, it is based on 2 dimensional lines. The surface itself is three dimensional in nature. 3D motif evaluation should be more suitable. Until now, no 3D motif evaluation method has yet been proposed. A key issue is 3D motif combination to determine how the evaluation should be implemented. Three types of 3D MOTIF combination methods currently used are examined. Features such as algorithm complexity and application range are investigated. We conclude that the best 3D Motif combination method is not currently available. We should select a combination method based on the need for surface function analysis. Hybrid methods are also recommended.