Shallowly buried urban tunnels with top opening are a type of green technique that saves energy.Four such tunnels have been built in Nanjing. The in?tunnel air quality has obtained extensive appraises since their being put into operation,but no regular design procedures has ever been developed. Based on a 1∶10 scale experimental platform,pressure pulsation and distribution in the tunnel were tested for 4 different working conditions. Results suggested that with a steady and continuous traffic flow, the time?wise pressure at each point in the tunnel was characterized by periodical and asymmetrical sinusoid?like pulsation. The amplitude of pressure pulsation decreased with increasing height. At a given moment with a steady and continuous traffic flow,the lengthwise pressure in the tunnel also displayed a periodical pulsation distribution pattern. It still existed periodical pressure pulsation with an attenuated amplitude in the vicinity of the top opening.