LongCite is an open-source model that trains large language models (LLMs) to produce accurate responses and precise sentence-level citations in long text question-answering scenarios. Its significance lies in enhancing the accuracy and credibility of question-answering systems, allowing users to verify the sources of the output information. LongCite supports context lengths of up to 128K and provides two models: LongCite-glm4-9b and LongCite-llama3.1-8b, trained respectively on GLM-4-9B and Meta-Llama-3.1-8B.