Objective: To explore sex difference in the cardiovascular health (CVH) status of 6-8 year old children in Beijing, so as to inform the early intervention of CVH related lifestyles. Methods: Based on the Beijing Children s Growth and Health Cohort (PROC), baseline physical examination, sequential questionnaire survey, and laboratory tests were conducted among 1 914 grade 1 students. Children s CVH and its subscales (health behaviors and health factors) scores were calculated according to the Life s Essential 8 (LE 8) index and categorized into high, moderate, and low CVH. CVH scores were reported as medians and interquartile ranges; sex differences were compared using the Chi square test and Wilcoxon test. Results: Among the 1 914 participants, the percentages of high, moderate, and low CVH were 35.7%, 63.5%, and 0.8%, respectively, and the percentages of high, moderate, and low health behavior scores were 25.9%, 67.5%, and 6.6%, respectively, with no statistically significant differences between sex ( χ 2=2.30, 0.07, P >0.05). The rates of high, moderate, and low health factor scores for boys and girls were 61.1%, 36.0%, 2.9% and 71.1%, 28.4%, 0.5%, respectively, with a statistically significant sex difference ( χ 2=31.88, P < 0.01). The overall CVH score was 76.0(70.0, 83.0), 76.0(69.0, 82.0) for boys, and 77.0(71.0, 83.0) for girls. Among the health behavior metrics, sleep scores were the best and physical activity scores were the worst[100.0(90.0,100.0), 40.0(20.0, 80.0 )]; among the health factor metrics, blood glucose scores were the best and lipid scores were the worst[100.0(100.0,100.0), 60.0(40.0,100.0)]. In respect to health factors, there were significant gender differences in body mass index, blood lipids, blood sugar, and blood pressure scores ( Z =-6.92, 3.01, -6.60, -2.30, <0.05), but there were no significant gender differences in diet, physical activity, nicotine exposure, or sleep scores with regards to health behaviors ( Z =0.99, 0.88, -0.13, 0.36, P > 0.05 ). Compared to boys, girls in the low and moderate CVH groups had high health factor scores despite low health behavior scores. Conclusion Most 6 to 8-year-old children in Beijing were found to have relatively good CVH, and optimization of children s CVH status can be achieved by promoting healthier lifestyles and monitoring health factors, especially among boys.