The influence of constant mechanical wind (CMW) and simulated natural wind (SNW) on human comfort and performance was investigated in a climate chamber. Eighteen subjects (twelve males and six females) were recruited. Four conditions with airflow were designed, including 28 °C with CMW and SNW, 30 °C with CMW and SNW. Two steady-state environments of 26 °C and 28 °C without airflow were also arranged for comparison. Performance was evaluated using three simulated office tasks – memory typing, addition and pattern matching. Subjects were required to finish questionnaires to evaluate their thermal sensation, thermal comfort, satisfaction of environment, workload and working motivation. The results suggested that both airflows would increase comfort in warm environments and the improvement effect was better at 30 °C than at 28 °C. SNW performed better for comfort and working motivation at 30 °C while CMW was better at 28 °C. The performance showed no difference under different environments except for few conditions in the addition task. The influence of CMW and SNW showed no significant influence on human performance.