The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan in Jeju Island, which is known as background area in Korea, from March 2010 to February 2011. The obtained results of asian dust events and non-asian dust period have been compared. The results show that the entire averaged aerosol number concentration from APS measurement during asian dust events and non-asian dust period are about 341 particles/$cm^3$ and 240 particles/$cm^3$, respectively. During asian dust events, the number concentration in small size ranges(${leq}0.4{mu}m$) are similar to non-asian dust period, however, those in large size ranges(${geq}0.7{mu}m$) are very higher than non-asian dust period. The contributions of the size resolved number concentration(23 channel in $0.25{sim}10.0{mu}m$) to total number concentration in that range are dramatically decreased with increased particle size. The contributions of smaller size ranges(${leq}0.4{mu}m$) during asian dust events are very low compared with non-asian dust period, on the other hand, those of larger size ranges(${geq}0.4{mu}m$) are higher than non-asian dust period. The number concentration in each size range are strongly correlated with the concentration in adjacent size range. And the total aerosol number concentration are depended on the number concentration in range of smaller than $0.58{mu}m$ during non-asian dust period and asian dust events. On the other hand, $PM_{10}$ mass concentration has mainly affected with the number concentration in range of smaller than $1.0{mu}m$ during non-asian dust period, however, during asian dust events, the mass concentration has mainly affected with the number concentration in range of $0.65{sim}3.0{mu}m$.