Pituitary glands from inbred neonatal rabbits were transplanted to the median eminence (group c) and the fundus of third ventricle (group d) of adult Nippon White rabbits. They were killed for histological examinations 1-2 months pos-toperatively

and comparison of ssrum prolactin (PRL) and thyroxine (T4) level between preoperation and preexecution was made.As the results

all grafts had survived with lymphocytic infiltration in two regions. The testing of PRL and T4 showed that there was no change of PRL and T4 value after operation in group c; while in group d

T4 level was obviously lower than normal after operation though PRL level kept almost the same. Our studies suggested that the grafts in group c recovered their normal endocrine functions

while the grafts in group d sho-wed no normal endocrine functions. The results indicated that the hytophysiotrop-hic area of hypothalamus is the best area for pituitary transplantation