Urban design is shifting towards space sharing to reduce the dominance of vehicles on roads. With this concept, it would not be uncommon to see pedestrians and vehicles mixed in traffic. This study aims to investigate the relationship between the traffic speed and density in shared spaces. The trajectories of road users in a mixed flow containing pedestrians, bicycles and powered two-wheelers were tracked and recorded. The speeds and densities of them were measured in microscopic approach in a two-dimensional manner due to the extremely different kinetic characteristics between pedestrians and vehicles. The density was calculated using the number of road users in the alert area of certain transport mode; the speed was calculated using the displacement per second. It is found that in the speed-density diagrams, the low speed and low density combinations occurred frequently, which were eccentric comparing to the conventional traffic flow theories. The reasons for such speed-density scattering patterns were discussed.