Abstract: To analyze the impact of linear upstream bus stop on traffic efficiency, the shockwave theory was employed to estimate car delays caused by linear upstream bus stop, when the traffic flow was stable. The car delays consist of two parts which take place at immediate upstream of bus stop and at signalized intersection. The additional car delays can be obtained as the difference between traffic flow effected by bus stop or not. Finally, the additional car delay model based on shockwave theory was implemented by the numerical analysis to get the relationship between additional car delays and some traffic parameters including traffic flow, bus dwell time, signal cycle and green ratio quantificationally. The results of numerical analysis show that the additional car delay increases along with the growing dwell time and traffic flow, and with the decreasing of signal cycle and green ratio. More specially, bus dwell time and traffic flow are major factors.