This study aims to evaluate the effect of ultra-low emission zone (ULEZ) on the demand of public bike sharing in London (also known as London Cycle Hire Scheme (LCH)). Bike usage data from 699 bicycle docking stations between May 2019 and October 2019 are used. Treatment and control groups for effectiveness evaluation of ULEZ are established using the propensity score matching approach, with which the confounding effects by factors including population density, socio-demographics, land use, and transport facilities are considered. Results indicate that bicycle demand increases significantly (27.9%) after the introduction of ULEZ. In addition, increases in bicycle demand are more profound for short (with 15 minutes, 25.3%) and intermediate (15 to 30 minutes, 28.8%) trips. Furthermore, increase in bicycle trip with origin (borrowing) and destination (return) both within ULEZ is considerable (44.8%). However, there is no significant change for overall bicycle trip duration after the introduction of ULEZ.