LexRel: Benchmarking Legal Relation Extraction for Chinese Civil Cases

Yida Cai, Ranjuexiao Hu, Huiyuan Xie, Chenyang Li, Yun Liu, Yuxiao Ye, Zhenghao Liu, Weixing Shen, Zhiyuan Liu


Abstract
Legal relations serve as an important analytical framework for dispute resolution in civil cases. However, legal relations in Chinese civil cases remain underexplored in the field of legal AI, largely due to the absence of comprehensive schemas. In this work, we first introduce a comprehensive schema for legal relations in civil cases, which contains a hierarchical taxonomy and definitions of arguments. Based on this schema, we formulate a legal relation extraction task and present **LexRel**, an expert-annotated benchmark for legal relation extraction in the Chinese civil law domain. We use **LexRel** to evaluate state-of-the-art large language models (LLMs) on legal relation extraction, showing that current LLMs exhibit significant limitations in accurately identifying civil legal relations. Furthermore, we demonstrate that explicitly incorporating information about legal relations leads to promising performance gains on other downstream legal AI tasks.
Anthology ID:
2026.acl-long.980
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
21440–21456
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.980/
DOI:
Bibkey:
Cite (ACL):
Yida Cai, Ranjuexiao Hu, Huiyuan Xie, Chenyang Li, Yun Liu, Yuxiao Ye, Zhenghao Liu, Weixing Shen, and Zhiyuan Liu. 2026. LexRel: Benchmarking Legal Relation Extraction for Chinese Civil Cases. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 21440–21456, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
LexRel: Benchmarking Legal Relation Extraction for Chinese Civil Cases (Cai et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.980.pdf
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