Jellyfish Nemopilema nomurai is a very dangerous animal because of its strong toxicity. It often bloomed in the coast of China in recent years and caused thousands of people stung and even deaths every year. However, the proteinaceous mixtures in nematocysts responsible for the symptoms of jellyfish stings were scarcely characterized and understood in view of enzymatic constituents and toxicity. 218 toxins were identified, including 47 phospholipase A2s and 33 metalloproteases by proteomics and transcriptomics approaches. Enzymatic properties of jellyfish N. nomurai nematocyst venom were analyzed biochemically and kinetically. N. nomurai nematocyst venom exhibited various enzymatic activities, of which metalloproteinases activity and PLA2s-like activity were predominant. Moreover, the catalytic activities of metalloproteinases and PLA2s-like were dependent on different physiochemical conditions such as temperature, pH and divalent ions. Kinetic profiling revealed their catalytic behaviors fitted the Michaelis-Menten equation under specific conditions. Findings suggested jellyfish nematocyst venom possessed diverse enzymatic constituents, which may underlie the extensively characterized bioactivities of jellyfish venom and human envenomations. Hence, our study will contribute to understanding the enzymatic constituents and toxicity of jellyfish nematocyst venom and may afford potential therapeutic targets for developing drugs for jellyfish stings.