The prevalence of asthma has dramatically increased in the last decades. Egyptian children aged 3 - 15 years was estimated to be 8.2%. Of major concern is a 10% annual increase in mortality. And probably, it is the most common cause of hospital admission for a respiratory complaint in adults. The aim of the present study is designed to find out safe and effective remedy to prevent asthma attack in susceptible patients from natural source. The total ethanol 70% extract of Euphorbia mauritanica L. was defatted using n- hexane. The non-polar fraction was analyzed by GC/MS technique. Metabolomics was performed using LC/HRMS analysis to identify the chemical components of this species. Antiasthma activity was studied in vivo on the extract. Asthma was induced by ovalbumin (OVA) sensitization followed by OVA challenge by intraperitoneal injection followed by intranasal challenge at day 20. Four groups of rats were used: 1st& 2nd groups for negative and positive control; 3rd& 4th groups were treated with the extract at 200 and 400 mg/kg orally concurrent with OVA sensitization and challenge. Measurement of Tidal Volume (TV) and Peak Expiratory Flow (PEF), MDA, GSH,IgE, IL-5, TNF-α and histopathology study were performed. Results of GC/MS analysis showed the presence of seven of the identified compounds are sesquiterpenes, one diterpene and one fatty acid ethyl ester. β-Vetivone is the major identified compound. LC/HRMS analysis identified 16 compounds including quercitin glycoside, oleanane terpenoids, phorbol acetate derivative and chlorogenic acid among the components. Results of antiasthma assay proved that Euphorbia mauritanica L. extract improved TV, PEF, GSH, reduced MDA, IgE, IL-5, TNF-α and alleviated histopathology changes produced by OVA. It is concluded that the identified components in Euphorbia mauritanica L. ethanol 70% extract are correlated with the interesting findings of results suggesting its role as antiasthma natural source