Abstract：The performance of large-scale antenna systems is affected by channel spatial correlation. Based on field channel measurement in an auditorium, this paper analyzes the channel correlation between different antenna elements in the array as well as different users. Antenna correlation coefficients with the antenna spacing are fitted with different models, and the factors that have impact on user channel correlation are also investigated.The results show that the antenna correlation coefficients in the array decays exponentially with antenna spacing in the horizontal plane. However, the antenna correlation tends to be a damped cosine wave in the vertical plane. In this paper, a model of negative exponential attenuation cosine is proposed to fit its modeling.Increasing the number of antenna introduces significant decrease in user channel correlation, especially when the number of antennais less than 30. The large-scale fading between different users degrades the channel orthogonality, and the fading is more severe in horizontal plane. Besides, the impact of large-scale fading over the array on user orthogonality is limited.