OBJECTIVE To investigate the efficacy of oral sweet solutions in relieving pain caused by vaccination in infants aged 1 to 12 months. METHODS Related databases were searched to find related randomized control trails (RCTs). The quality of these RCTs was evaluated. The Meta analysis was performed using RevMan 5.3. RESULTS A total of 20 RCTs involving 2 376 infants were included, and quality assessment showed that 6 RCTs had grade A quality and 14 had grade B quality. The Meta analysis showed that compared with sterile water, 25%-75% oral sweet solution significantly reduced crying time (WMD=-21.16, 95%CI -39.66 to -2.77, P<0.05) and the proportion of crying time (the duration of crying /3-minute periods after the injection) (WMD=-13.83, 95%CI -20.88 to -6.78, P<0.01), while the crying time showed no significant difference between the group treated with oral administration of 12% sucrose solution and non-intervention group. Co ONCLUSIONS Oral sweet solution (25%-75%; 2 mL) given 2 minutes before vaccination can effectively relieve the pain caused by vaccination in infants aged 1-12 months.