Submerged macrophytes are important primary producers in aquatic ecosystems and play an important role in maintaining clean water, nutrient cycling, and ecosystem structure. Ecological stoichiometry is used to study the relationships between the balance of several chemical elements and energy in ecological interactions. At present, the research on the stoichiometric characteristics of submerged macrophytes focus on non-karst areas, but it is a lack of research on karst wetland. To research community level stoichiometric characteristics of submerged macrophytes and their factors, the study analyzed the submerged macrophytes and sediment in Chengjiang karst wetland in Guangxi, southwestern China. Results showed that (1) the mean contents of total carbon (TC), total nitrogen (TN) and total phosphorous (TP) of seven submerged macrophytes were (297.59±4.38) g/kg, (29.78±0.52) g/kg and (3.4±0.13) g/kg, respectively. The highest contents of TC, TN and TP were in Najas minor with (325.4±5.01) g/kg, (33.07±1.59) g/kg and (3.79±0.16) g/kg, respectively. The mean ratios of C:N, C:P and N:P of submerged macrophytes were 10.14±0.18, 96.23±3.56 and 9.47±0.32, respectively. The highest C:N ratio was in Vallisneria natans (11.89±0.54), while the highest ratios of C:P and N:P were in Myriophyllum spicatum (113.27±18.14 and 11.13±1.63). (2) The mean contents of soil organic carbon (SOC), TN, TP, alkaline hydrolysis nitrogen (AN) and available phosphorus (AP) of sediment were (15.05±0.56) g/kg, (2.06±0.08) g/kg, (0.58±0.01) g/kg, (162.53±9.16) mg/kg, and (21.73±0.86) mg/kg, respectively. The highest contents of SOC, TN, TP, AN and AP were in N. minor with (18.54±1.04) g/kg, (2.55±0.25) g/kg, (0.66±0.03) g/kg, (214.82±32.05) mg/kg and (26.37±3.31) mg/kg, respectively. The mean ratios of C:N, C:P and N:P of submerged macrophytes were 7.33±0.14, 25.7±0.72 and 3.53±0.09, respectively. The highest ratios of C:N, C:P and N:P were in Ceratophyllum demersum (7.45±0.32), N. minor (28.29±1.29), and Hydrilla verticillata (3.89±0.25). (3) There were significantly negative correlations between TC of submerged macrophytes and SOC, TN of sediment, while significantly positive correlations were found between TN of submerged macrophytes and SOC, AN and C:P of sediment. In addition, ratios of C:N and C:P of submerged macrophytes showed significantly negative correlation with the SOC, TN, TP, AN, C:P and N:P of sediment, indicating that nutrient correlations are different between submerged macrophytes and sediment. Based on the ecological stoichiometric, it was preliminarily inferred that V. natans and M. spicatum may be more suitable as pioneer species for the restoration of submerged macrophytes in eutrophic karst wetland. The results support the research of ecological stoichiometry wetland ecosystems in karst areas.