Abstract： Objective To investigate the clinical effect,suitable dose,and its safety of dezocine combined with propofol used in painless artificial abortion.Methods With a completely randomized double blind method,200 cases of ASA Ⅰ or Ⅱ early intrauterine pregnancy patients were divided into A,B,C,and D four groups ( n =50).Each patient in A,B,and C groups was infused dezocine in 0.10,0.15,and 0.20 mg/Kg,respectively.D group was administrated with intravenous fentanyl 1.5 μ g/kg,then 3min later,slowly intravenous injection of 1％ of propofol.MAP,HR,RR,and SpO2 were recorded at the before anesthesia induction (T0 ),loss of eyelash reflex time (T1 ),recovery time (T2),and recovery 10 -min time (T3 ).Meanwhile,the parameters including the anesthesia induction time,anesthesia recovery time,directional force recovery time,induction dosage and total dosage of propofol,and the intraoperative and postoperative analgesic efficacy and adverse reaction were compared among different groups.Results For the A and D groups,MAP,HR,RR,and SpO2 at the T1 were all lower than that at the T0 ( P ＜0.05).For the B group,MAP and HR at the T1 were lower than that at the T0 ( P ＜ 0.05).The anesthesia recovery time and orientation recovery time in the B and C groups were significantly shorter than A and D groups ( P ＜ 0.05 ),and significantly statistical difference was found between A and D groups,no statistical difference between B and C groups ( P ＞ 0.05).The propofol induction dosage and total dosage were different among groups ( groups C ＜ B ＜ D ＜ A) with a statistical significance ( P ＜ 0.05 ).The intraoperarive analgesia effect,postoperative pain score grading,and intraoperative body dynamic reaction rates in the B and C groups were significantly different from the A and D groups ( P ＜ 0.05 ),and no statistical significance was found between B and C groups ( P ＞ 0.05 ).The respiratory inhibition,postoperative nausea,vomiting and other adverse reaction rates in the B and C groups were significantly lower than those in A and D groups ( P ＜ 0.05),and those parameters in B group were lower than C group.Conclusions Dezocine combined with propofol is definitely effective and very safe in painless induced abortion with very less respiratory inhibition,nausea,vomiting,and other adverse reactions; and their optimal dosage is 0.15 mg/kg.