Abstract: Cerebrospinal fluid pressure (CSFP), respiration and palpitation of ten healthy miniature dogs respectively recorded on the condition of anesthesia and injecting contrast media (OMNIPAQUE(r) iohexol, 300 mg I/mL) into subarachnoid space. CSFP variations were according to respiration and palpitation. In addition, it was primarily affected by respiration, and take on a cycle in one respiration. CSFP was remarkably improved during injecting contrast media into subarachnoid space, and the range of CSFP variations were enlarged.