CONTEXT: Handgrip strength (HGS) is an important indicator of sarcopenia and adverse health outcomes. However, evaluating HGS in children presents challenges, and its association with metabolism remains incompletely understood. OBJECTIVE: To establish grip strength reference values for Chinese children and adolescents, as well as to evaluate the relationship between HGS and cardiometabolic risk. METHODS: Data were collected from 4 072 participants aged 6-18 as part of the Evaluation and Monitoring on School-based Nutrition and Growth in Shenzhen (EMSNGS) study. HGS was measured, and relative HGS (RHGS) was normalized by body mass index. Age- or weight-specific HGS and RHGS were derived using the generalized additive model of location, scale, and shape model, and participants' values were categorized into quartiles, defining low strength as the lowest quartile. The cardiometabolic risk index (CMRI) z-score was calculated, with high risk defined as a z-score of ≥1. RESULTS: Both boys and girls exhibited similar increases in age- and weight-specific grip strength. Low grip strength, classified by weight-specific HGS and RHGS, was linked to higher CMRI z-scores than classifications based on age-specific references in both sexes. A dose-dependent relationship was observed between weight-specific grip strength and cardiometabolic risk, particularly in boys. Compared with the middle category (P25th-P75th), the odds ratios for high cardiometabolic risks associated with low grip strength increased in both sexes. CONCLUSION: This study established grip strength reference values for Chinese youth, introduced the concept of weight-specific HGS and RHGS, and demonstrated a dose-dependent relationship between weight-specific grip strength and cardiometabolic risk. These findings highlighted the association between low muscle strength and increased cardiometabolic risk.