Among the newly discovered spinocerebellar cell groups, theose at lumbar and more caudal levels of the cat's spinal cord were studied with regard to which of the two cerebellar peduncles, the restiform body or the superior cerebellar peduncle, is used by theri axons. Bilateral injections with horseradish peroxidase were made into either of the anterior lobe or the posteriosr cerbellar termination area for spinocerebellar fibers, following unilateral transections of either the superior serebellar peduncle or the resiform body, combined with low contralateral transecions of the lateral and ventral funiculi. Following transection of the superior cerebellar peduncele, labeled neurons were found ipsilateral to the transection in the colun of Clarke and in laminas IV-VI at L3-L7. Contralalterally, labeled neurons were found in the ventromedial nucleus and lamina and in the medial part of lamina VII at L6 and more caudal levels. All these neurons were regarede as semding their axons through the restiform body. Followitn transection of the restiform body, labedled neurons were found in the following areas contralateral to the transection: the dorsolateral nucleus of the L3-K6 segments, the lateral part of lamina VII at L3-L5/6, the medial part of lamina VII in L6 and more caudal segments, and the ventrolatreal nucleus of L4-L5. Ipsilaterally, labeled neurons were found in lamina VIII at L4-L6. All these neurons were regarded as sending their axons through the superior cerebellar peduncle. In addition to new information about the peduncular routes of spinocerebellar neurons, the study has given confirming evidence as to the crossing conditions for different spinocerebellar cell groups. The findings should be useful future studies on the organization of the spinocerebellar system.