The study was conducted to know the change in airway resistance of 158 patients more than 5 years old with asthma after using inhaled salbutamol going to hospital to examination, treated and counseled at the pneumology Department of Saint-Paul Hospital from 1st Sep 2009 to 31st Oct 2010. Results showed that the most frequent age was from 5 to 9 years old. 61.4 percent of children with asthma attacks and 38.6 percent in children with asthma attack outside. The airway resistance of inrespiratory and exrespiratory periods in both asthme outside attacks and asthma attacks tend to decrease with age. Group of children with asthma attack had an airway resistance higher than the group outside attack. After using inhaled Salbutamol, airway resistance of asthmatic children in the attack group in inrespiratory and exrespiratory periods was higher than the group of children with asthma outside attacks (p 0.05). In conclusion, resistance airways both the inrespiratory and exrespiratory periods decreased with age. After using inhaled Salbutamol, airway resistance of asthmatic children in inrespiratory and exrespiratory periods were clearly reduced. The airway resistance of asthmatic children attacks and outside attacks were decreased. After using inhaled Salbutamol, airway resistance of asthmatic children in the attack group was higher than the group of children with asthma outside attacks.