Ｏｂｊｅｃｔｉｖｅ　To evaluate the effects of bupivacaine combined with sufentanil citrate or dexmedetomidine on spinal anesthesia in transurethral resection of the prostate.　Methods　A total of ninety American Society of Anesthesiologists(ASA) Ⅰ or Ⅱ patients aging 65-75 y and body mass index(BMI) 20-30 kg/m2 who were scheduled for transurethral resection of prostate (TURP) were randomly divided into three groups (n=30): a dexmedetomidine group (group D), a sufentanil group (group S), and a normal saline group (group N). After spinal anesthesia with bupivacaine, dexmedetomidine (5 μg) was intrathecally injected in group D, sufentanil (5 μg) was intrathecally injected in group S, and group N received the same volume of normal saline. The blockage onset time and duration were recorded. The Richmond Agitation Sedation Scale (RASS) scores, shivering, nausea, vomiting and other adverse effects during and after operation were also recorded.　Results　There were no significant differences in age, BMI, operation time, transfusion volume, blood loss, and RASS scores among the three groups (P>0.05). Group S demonstrated remarkably high incidences of nausea and vomiting, compared with group N and D (P<0.05). Compared with group N, groups S and D presented remarkably decreases in the sensory blockage onset time, and increases in the blockage duration (P<0.05), and markedly reduced motion blockage onset time and extended duration(P<0.05).　Conclusions　Spinal anesthesia of bupivacaine combined with sufentanil or dexmedetomidine can produce good effects on TURP patients. However, patients compound dexmedetomidine got less side effects like shivering, nausea and vomiting.