Two different aerosol mass spectrometers,Aerodyne Aerosol Mass Spectrometer (AMS) and Single Particle Aerosol Mass Spectrometer (SPAMS) were deployed to identify the aerosol pollutants over Xiamen,representing the coastal urban area.Five obvious processes were classified during the whole observation period.Organics and sulfate were the dominant components in ambient aerosols over Xiamen.Most of the particles were in the size range of 0.2-1.0 μm,accounting for over 97％ of the total particles measured by both instruments.Organics,as well as sulfate,measured by AMS were in good correlation with measured by SPAMS.However,high concentration of NH4+ was obtained by AMS,while extremely low value of NH4+ was detected by SPAMS.Contrarily,high particle number counts of NO3-and Cl-were given by SPAMS while low concentrations of NO3-and Cl-were measured by AMS.The variations of POA and SOA obtained from SPAMS during event 1 and event 2 were in accordance with the analysis of HOA and OOA given by AMS,suggesting that both of AMS and SPAMS can well identify the organic clusters of aerosol particles.Overestimate or underestimate of the aerosol sources and acidity would be present in some circumstances when the measurement results were used to analyze the aerosol properties,because of the detection loss of some species for both instruments.