Local food has become the foci of food self-sufficiency and sustainable development. This work explores the dynamic interactions between local and imported food in Hawaii, which is a typical small, open economy and an ideal market for a local food system study. Retail scanner data of three major grocery chain stores are used to construct a time series of prices and quantities for local and imported grape and cherry tomatoes in one year (52 weeks). Vector Autoregressive model and impulse response functions are used to investigate the correlations and Granger causalities. Empirical results provide implications for the competitive status of local suppliers and the dynamics of the local food market.