LABORATORY and wirehouse experiments were conducted in Weed Research CentralLaboratory, Agricultural Research Center, Giza, Egypt to investigate the possibility of using microwave energy to prevent the germination of weed seeds and find applicable treatments which can completely devitalize quarantine weed seeds. The present work evaluated the effect of microwave on germination of six weed species: wild oats, darnel, white bursage, Giant ragweed, field bindweed and dodder and improvement of some traits of two imported crops soybean and wheat (oil percentage of soybean seeds and protein content of wheat grains), which were contaminated by these weed species. Results showed that microwave power and time required for preventing germination varied considerably among the species studied. Microwave power 80% for 15min prevented completely germination percentage of wild oats and darnel and reduced germination percentage of field bindweed to 10%. The microwave power 50%, 15min was enough to prevent seeds germination completely and weaken dooder quarantine. In regard to Giant ragweed and white bursage, under all microwave power treatments, there were no germination of these weeds. Microwave powers 50% for 10min and 80% for 15min had no effect on the oil percentage extracted from soybean seeds and protein content of wheat grains, respectively. The present results suggest clearly that the exposure to microwave can weaken quarantine weed seeds in imported soybean and wheat without injury of oil percentage of soybean seeds and protein content of wheat grains.