The geometrical structures and electronic properties of GenB (n=12—19) clusters have been studied using first principles with generalized gradient approximation. The results show that GenB (n=12—19) clusters have large energy gap. The lowest energy structures of GenB (n=12—19) clusters have two different element, such as Ge9 and Ge10, cluster configuration. There are two different models capable of forming GenB clusters, which are the cluster with B atom concaved in Gen, and the cluster in which B substitutes Gen+1. 17 is the magic number of GenB (n=12—19) clusters.