The main purpose of this paper is to examine the application of dynamic copulas and artificial neural networks on multivariate intraday returns. The estimation of the parameters is a sequential process. In each of the experiment, we first apply artificial neural networks to estimate a marginal model and then apply dynamic copulas. In applying artificial neural networks, we found that periodicity is important in modeling the degree of freedom. In applying dynamic copulas, we examine whether the correlations are time-varying and what kind of dynamics the correlations exhibit. We found that the correlations for intraday returns are nonlinear and time-varying in two experiments. After applying dynamic copulas and artificial neural networks, we constructed portfolios based on the predicted means and covariance matrices. We found that the portfolios constructed outperform equally weighted portfolios in two experiments.