Abstract of thesis entitled “Empirical Comparisons of the Functional Forms of Intertemporal Demand Systems”, submitted by Gao Long (M-B1-5639-9) for the degree of Master of Social Sciences in Economics at the University of Macau in June 2014. This study analyzes the consumer behavior empirically from both Micro and Macro levels. Based on the framework of intertemporal two-stage demand theory, we jointly estimated six demand systems and the associated Euler equations using annual US time series data. To measure the performances of these different demand systems, we applied several information criteria. The best fitted model is then used to estimate income and price elasticities, and the coefficient of relative risk aversion. Results show that all six models performed well on explaining the budget shares, and most criteria provide evidence that the Almost Ideal Demand System (AIDS) is the best fitted model.