Abstarct: Abstract Nowadays, the use of environmental protection methods such as application of biological elicitors and fertilizer in sustainable and organic agriculture has received considerable attention because of their bioactivity and safety for the environment and especially for humans. In order to investigate the effect of symbiotic Funneliformis mosseae and Piriformospora indica (new scientific name: Serendipita indica) along with foliar application of the yeast extract (Saccharomyces cervisiae L.) on the yield and yield components of sweet corn and the activity of some soil enzymes, an experiment was designed and implemented in the field.. The experiment was carried out in 2018 and 2020 as factorial baxsed on randomized complete block design with three replications. The experimental factors include fungi in four levels of arbuscular mycorrhizae (Funneliformis mosseae), P. indica, combined application of mycorrhizal fungi and P. indica and control, spraying of yeast extract at four levels of non-consumption (control), 2, 4 and 8 g/l of yeast extract as the second factor. The results showed that the main effect of fungi on all the traits studied in this research was significant, Foliar spraying of yeast extract in both years led to a significant increase in most studied traits, including vegetative traits, yield and yield components, and some physiological traits. The symbiotic relation between fungi and plants increased the chlorophyll content, protein content and phosphorus in sweet corn grains. The effect of the combined use of two mycorrhizal fungi F. mosseae and P. indica on some traits such as plant dry weight, grain yield, alkaline phosphatase enzyme and soil urease in 2017 and leaf area index, plant dry weight and alkaline phosphatase in 2019 It was remarkable ,So that combined use of F. mosseae and P. indica increased available soil phosphorus by 62% and 85% in 2019 and 2020 respectively and alkaline phosphatase was increased by 74.2% (2018) and 80.5% (2020). The interaction of fungus and foliar spraying of yeast extract caused a significant increase in plant dry weight in 2017 and leaf area index in 2019. The results of this research showed that by using internal symbiotic fungi, especially the combined use of mycorrhizal fungi F. mosseae + P. indica and foliar spraying of yeast extract at the levels of 4 and 8 g/l can achieve optimal performance that protects human health by increasing the activity of soil enzymes while maintaining the health of the soil and plant.