In this paper, new modified ranked set sampling method is suggested for estimating the population mean, namely, stratified quartile ranked set sampling (SQRSS). The SQRSS is compared with simple random sampling (SRS), stratified simple random sampling (SSRS) and stratified ranked set sampling (SRSS) methods. It is found that the SQRSS estimators are unbiased of the population mean of symmetric distributions. Also, it turns out that the SQRSS is more efficient than its counterparts using SRS, SSRS and SRSS based on the same number of measured units.