The CCIS book constitutes selected papers of the 12th International Conference on Computational Science and Computational Intelligence, CSCI 2025, which took place in Las Vegas, NV, USA, during December 3–5, 2025.

The 40 full papers included in this book were carefully reviewed and selected from 294 submissions to the Research Track on Large Language Models, CSCI-LLM.

They were organized in topical sections as follows: Large Language Models, Knowledge Graphs, Prediction Methods, and Learning Methods; Large Language Models, Natural Language Processing, Security Methods, and Applications; Large Language Models, Data Science, and Related Issues; and Large Language Models, Artificial Intelligence, and Applications.