Objective: To learn the characteristics of adolescent pregnancy in Wenzhou from 2015 to 2019, so as to provide basis for protecting adolescent physical and mental health. Methods: Data of demographic characteristics, pregnancy and delivery outcomes of the women aged under 19 years ( adolescent pregnant ) and 20 to 34 years ( right-age pregnant ) who delivered in Wenzhou from 2015 to 2019 were collected from Wenzhou Maternal and Child Health Information Management System. The incidence of pregnancy complication, comorbidity and adverse delivery outcomes of adolescent pregnant women was compared with that of right-age pregnant women. Results: Among 536 753 parturients reported in Wenzhou from 2015 to 2019, there were 22 419 ( 4.18% ) of adolescent pregnancy and 430 163 ( 80.14% ) of right-age pregnancy. The average age of adolescent pregnant women was (18.11±0.82) years ( range, 10-19 years ). The majority of adolescent pregnant women were migrant population (19 437 cases, 86.70%), had an education level of junior high school and below ( 18 594 cases, 82.94% ), and had no occupation (19 192 cases, 85.61%). The incidence rates of anemia, gestational diabetes, postpartum hemorrhage, perineal laceration and premature delivery in adolescent pregnant women increased from 2015 to 2019 ( all P<0.05 ). The incidence rates of gestational diabetes, anemia, gestational hypertension, placental abruption, postpartum hemorrhage, perineal laceration, premature delivery, low birth weight, fetal death and stillbirth were 1.65%, 11.76%, 0.19%, 0.26%, 3.19%, 24.52%, 6.03%, 5.53%, 0.50% and 0.04% in adolescent pregnant women, which were significant different from 5.49%, 8.94%, 0.13%, 0.01%, 0.17%, 23.46%, 4.66%, 3.08%, 0.26% and 0.01% in the right-age pregnant women, respectively ( all P<0.05 ). Conclusions The adolescent pregnant population in Wenzhou are mainly migrant population with lower education level and no occupation. The incidence rates of pregnancy complication, comorbidity and adverse birth outcomes in adolescent pregnant population are higher than those in right-age pregnant population, and are increasing year by year.