Abstract: Transient mode emissions from twelve inland ships were measured using a portable emissions measurement system (PEMS). The results show that the emissions of CO, HC, and PM during cruise mode were 0.093,0.019, and 0.018g/s, respectively, lower than the emissions in maneuvering and departure modes. In contrast, the NO_x emission factor in cruise mode was 0.347g/s, which was 1.66and 2.90times of the emissions in maneuvering and departure modes, respectively. The ratios of NO to NO_x varied under different conditions. The proportion of NO was maximum in cruise mode (reaching 96.7%), while the proportions in maneuvering and departure modes were 93.6% and 93.1%, respectively. CO, HC, NO, and PM emissions from the vessel increased with load; the emissions concentrations in high load mode were 89.23%,29.51%,44.72%, and 229.49% higher, respectively than those in low load mode. Particle number (PN) distribution analysis indicated that the number distribution showed a double peak logarithm distribution consisting of accumulation mode/coarse mode and nucleation mode/accumulation mode. Particles smaller than 120nm consisted of 99.84% of all particles by number. Among PM₁₀ particles, 99.9% were PM_2.5.