Path planning for robots with obstacles is an important problem and have not been resolved well yet. An extended Support Vector Machine(SVM)-based path planning method(which is named the multi-constraints SVM method in this paper) was proposed in previous work. However, no analysis was provided for the planned paths. So, an detailed analysis of the paths based on the method above will be given in the paper. The continuity of curvature and uncontinuity of the first order derivation of curvature for the planned paths will be mainly discussed in the paper. What's more, the relationship between the uncontinuous points of the first order derivation of curvature and the focuses for human driving behavior will be discussed. Based on that, an important conclusion about the support vectors and the focuses for path following is derived, and it is believed to be important for the path following problem. The correctness of the analyzing results and the effectiveness of the path planning method were verified through simulation results.