Compaction or soil compression in agriculture is one of the most important problems which may occur in a wide range of soils. By reducing the soil organic matter content and high traffic at high humidity, soil compaction is intensifying. The problem of soil compaction and compression is one of the major difficulties and limitations of the soil green space in Isfahan city. The purpose of this study was to evaluate the effect of mycorrhizal fungi and PGPR (Plant Growth Promoting Rhizobacteria) on different levels of relative soil compacted for the cultivation of perennial ryegrass (Lolium perenne L .) and marked effect of these microorganisms and relative soil compaction levels on morphological and physiological characteristics of this grass. The present research was conducted in 2014-2015 in Isfahan University of Technology on perennial ryegrass. In this study, a factorial experiment based on a completely randomized design with three replications was conducted in two successive years. Factors included 5 levels of microorganisms (control, Glomus mosseae , G. intraradices , and two types of PGPR business including Pseudomonas putida (R4) and P. putida (R8)) and two levels of relative soil compaction (0.87-0.70). After full deployment and topping grasses, drought stress in the form of irrigation termination was done. Measurement of morphological parameters, began from the beginning to the end of the growing season grasses. Measurement of relative water and chlorophyll content was done in two times, before the irrigation cut and 50% necrosis of the turfgrass, The other physiological measurements was done at 50% necrosis of the turfgrass. The results showed that the drought stress, Irrespective of the relative soil compaction level have been significant negative effect on most of the morphological and physiological indices. In terms of morphological parameters, plants inoculated with mycorrhiza, color of turfgrass and plants inoculated with PGPR, turfgrass density was significantly increased relative to control. Also Turfgrass inoculated with bacteria growth significantly increased proline and reducing MDA content compared to control. In conclusion, the compacted soil 0.87 significantly improved the majority of morphological and physiological indicators relative to the level of soil compaction 0.70, probably because of the proximity of this level, is ideal to the level of compression for the cultivation of this species of grass. Keywords: perennial ryegrass, relative soil compaction, drought, mycorrhizal fungi, PGPR, morphological and physiological indicators