Marco-o1 is an open large inference model designed to optimize the resolution of complex real-world problems using advanced technologies such as Chain-of-Thought (CoT) fine-tuning, Monte Carlo Tree Search (MCTS), reflective mechanisms, and innovative reasoning strategies. This model focuses not only on disciplines with standard answers such as mathematics, physics, and programming, but also emphasizes the solution of open-ended questions. Developed by the MarcoPolo team at Alibaba International Digital Commerce, Marco-o1 demonstrates exceptional performance across various fields with strong inference capabilities.