Abstract: The projection from nucleus subpre-tectalis/nucleus interstito-pretectalissubpretectalis (SP/IPS) to nucleus rotundus (Rt) is an important part of avian visual pathway. To reveal the morphological features of SP/IPS cells (S cells) which project to Rt, they were retrogradely labeled with cyanine perchlorate DiI in chicks. Two different types of neurons, “type Ⅰ cells” and “type Ⅱ cells” were identified. Based on the amount of the secondary dendrites, these cells were further divided into simple and complex cells, respectively．Morphological analysis indicated that the type I cells were smaller and fewer than type Ⅱcells.