Uncertain flow analysis is becoming prevalent in various scientific and engineering domains, such as computational fluid dynamics, aerodynamics, climate, and weather research. In uncertain flow fields, a spatial location often contains a distribution of possible vector directions, which makes traditional flow analysis techniques difficult to apply. In this project, we proposed various techniques to analyze and visualize uncertain flow behaviors, including uncertain Finite-Time Lyapunov Exponent (FTLE) calculation and visualization, uncertain Lagrangian Coherent Structure (LCS) extraction, and density estimation of uncertain stream surfaces.