Abstract: In this paper, the fuzzy C-means clustering algorithm(FCM), the induced fuzzy C-partition algorithm(IFCM), the hierarchical clustering algorithm based on asymmetric similarities(HCAM), and the algorithm for detecting unimodal fuzzy sets(GFAM) are described. The clustering results of several experimental data sets are given. The properties of these algorithms are also discussed. The results obtained indicate that HCAM is the most powerful algorithm of the four, and that GFAM is more powerful than FCM and IFCM,