The lichens in the genera Collema and Leptogium are characterized by having a soft gelatinous (when wet) thallus with a nitrogen-fixing cyanobacterium as the photobiont component belonging to the genus Nostoc. The aim of this study was to survey the diversity of lichen genera Collema and Leptogium in Taiwan. During the course of study from November 2007 to April 2009, four new records have been found. They were C. rugosum, L. burgessii, L. rugosum and L. tenuissi-mum. For the species obtained in this study, all the discernible characters, such as thallus, isidia, apothecia, asci and as-cospores were observed, described and photographed. It was expected that a clear guideline of identification can be es-tablished.