Objective To investigate the changes of 24-h ambulatory blood pressure monitoring (ABPM) in children with postural tachycardia (POTS). Methods Retrospective analysis of 70 children with POTS (POTS group), 31 males and 39 females, aged (4-14) years, with a mean age of (11.14±2.22) years, who were seen in the outpatient clinic or hospitalized for unexplained syncopal aura and syncope symptoms from January 2009 to June 2013, and were diagnosed clearly by the upright tilt test (HUTT) and underwent ABPM at the same time. Forty healthy children, 22 males and 18 females, aged (4 to 14) years, with a mean age of (10.60 ± 2.38) years, who came to the clinic for health examination at the same time were matched according to age and sex (control group). The children in both groups were subdivided into a “spoon” blood pressure subgroup and a “non-spoon” blood pressure subgroup according to the circadian rhythm of blood pressure. Statistical analysis was performed using SPSS17.0 software. Results (1) Mean blood pressure: The mean systolic blood pressure, mean diastolic blood pressure, mean daytime systolic blood pressure, mean daytime diastolic blood pressure, mean nighttime systolic blood pressure, and mean nighttime diastolic blood pressure were slightly lower in the POTS group than in the control group (P>0.05). The diurnal difference in systolic blood pressure was lower in the POTS group than in the control group (P<0.05), while the diurnal difference in diastolic blood pressure was not statistically different in the two groups (P>0.05). (2) Circadian rhythm of blood pressure: “non-spoon” blood pressure was higher in the POTS group than in the control group (72.9% vs. 45.0%, P<0.01). blood pressure subgroup was higher than that of the "non-spoon" blood pressure subgroup (P<0.05), while the mean nighttime systolic blood pressure and mean nighttime diastolic blood pressure were lower in the "spoon" blood pressure subgroup than in the "non-spoon" blood pressure subgroup (P<0.05). subgroup (P<0.05). Conclusion The mean blood pressure of children with POTS was not significantly different from that of healthy children, but the circadian rhythm of blood pressure in children with POTS was more common in the "non-spoon" blood pressure.