1. Introduction

2. The MaxBCG cluster correlation functions
2.1. The MaxBCG cluster catalog
2.2. Estimation of the two-point correlation function

3. A model for the cluster correlation function
3.1. Non-linear evolution and bias
3.2. Effects of photometric redshift errors

4. The covariance matrix

5. Results
5.1. Estimate of the correlation length
5.2. Correlation function on large scales
5.3. Cluster bias

6. Conclusions