Transgenic mice are valuable tools to label selective neuronal or non-neuronal populations, modulate gene expression in these cells or manipulate activity of these cells for the study of neural circuits and brain function. The Allen Institute has launched a project to generate a variety of transgenic mouse lines, mainly using the Cre/lox system, to express fluorescent probes or neuronal activity manipulating tools in a variety of cell types in the brain. At the same time, utilizing Allen Institute’s unique high-throughput capability, a pipeline is set up to characterize the ability in directing cell type specific expression in the brains of various transgenic mice generated by the Allen Institute as well as the broad scientific community. Through standardized, detailed, anatomical profiling of the transgene expression in the entire mouse brain, this dataset is intended to provide a comprehensive evaluation of the potential of each transgenic mouse line and help researchers choose the appropriate transgenic tools to study the function of different regions and/or cell types of the brain.