Design storm is one of the most important tools in designing hydraulic structures and hydrological studies such as flood control, collection and disposal systems for urban surface water which is acquired for a given duration and return period using the intensity – duration – frequency (IDF) curves. Recording rain gauges measure the storms data. There is no recording rain gauge in many areas parts of the country and sometimes the existing rain gauges have a short-time recorded data making it impossible to extract IDF curves. It is possible to extrapolate the amount of rainfall for other ungaugged regions using some conventional methods and recorded data of other existing rain gauges. However, these data have some errors and to solve this problem, the investigators have proposed the IDF empirical equations. Having various accuracy, the given methods have different functions which cause decrease or increase of error in outputs. The methods which take into account the rainfall frequency distribution indicated a more accuracy in comparison with other methods. One of these methods is the scaling theory for extracting IDF curves using the 24 maximum rainfall. In this study, the IDF curves for short- duration rainfall have been obtained using time-scale characteristics of the rainfall which is acquired through daily precipitation. The theory which uses the average, standard deviation and scaling exponent to estimate IDF curves. This method has less computational compared to traditional methods and results in steps and parameter causes increasing in reliability of IDF curves. This method (Scaling method) was used to extract the IDF curves in recording rain-gauges in Chaharmahl Bakhtiari province( Aloni, Boroojen, Farsan, Shahrekord and Chelgerd) which shows the efficiency and robustness of the scaling method. The Gumbel, exponential and Generalized Extreme value distributions were used. In this study, the amount of theoretical error with observations in Chaharmahal Bakhtiari province have been calculated and reported using RMSE index for basic duration (5 to 1440 minutes) with RMSE values from 1.93 to 13.76 and for for different return periods (2 to 200 year) with RMSE ranging from 11.2 to 18.58 . Furthermore, the other advantage of this method is the possibility of creating an spatial distribution map using the regional IDF curves which are estimated from three variables of (?,_24 )، ?_24 (H). It is practical to estimate the amount of these parameters ungagged regions or catchments to define ant extrac IDF curves. Results also showed that the rainfall intensity average and standard deviation reduce from North West to the south and south east. Keywords: Chaharmahal and Bakhtiari, Design storm , Frequency analysis, IDF curves, Scaling method.