Using Stroop-like tasks, this study examined whether Chinese kindergartners showed automatic processing of numerical magnitude. A total of 36 children (mean age = 5 years 10 months) were asked to perform physical size comparison (i.e., "Which of two numbers is bigger in physical size?") and numerical magnitude tasks (i.e., "Which of two numbers is bigger in numerical magnitude?") on 216 number pairs. These number pairs varied in levels of congruence between numerical magnitude and physical size (for Stroop effect) and numerical distance (for distance effect). On the basis of analyses of response time and error rates, we found that Chinese kindergartners showed automatic processing of numerical magnitude. These results are significantly different from previous studies' findings about the onset age (ranging from around the end of first grade to third grade) for automatic processing of numerical magnitude.