Twelve species of Mortierella are presented, which were obtained during a long term study of Zygomycetes in Taiwan. They are Mortierella alpina, M. ambigua, M. biramosa, M. capitata, M. elongata, M. exigua, M. gamsii, M. gemmifera, M. globulifera, M. jenkinii, M. parvispora and M. zychae, nine species among which are new records, namely Mortierella alpina, M. biramosa, M. capitata, M. elongata, M. exigua, M. gamsii, M. gemmifera, M. globulifera and M. zychae. Identification was based on morphological characters. A phylogenetic tree of Mortierella was constructed based on the analysis of ITS rDNA sequences (ITS1-5.8S-ITS2) and a key to the species of Mortierella from Taiwan is also provided.