The study aims to know the relationship between internet addiction and insomnia to tenth graders in Alsharqiya North in Sultanate Of Oman. The sample of study consisted of 553 students, (292) of males and (261) females whom are chosed randomly. The tools of study consisted of the scale of internet addiction and the scale of insomnia and it has reached the following results. -The number of internet addicts reaches 48 male and female students with a persentage of 8,7% with the number of the non addicts is 505 male and female with a percentage of 91,3%. -The number of insomnia is 121 male and female students , while the number of non-insomniacs is 431 male and female students. -The existence of adirect correlation that is positive and statistically significant at the significance level (a≤1.15 )between internet addiction and the level of insomnia to tenth graders. -There is no statistically significant differences at the level of significance (a ≥1.15) between the internet addicts group and the non-addicts group in the first, second ,third , fourth and sixth measure. However , the results have proved the existence of differences in the fifth measure start of sleeping -Most of the study sample use the internet within just one hour in every (38) hour while many of them also use it from 2-5 hours.However, the number of the least sample is divided between the number of hours of use from 6-20 hour. -There are no statistically significant differences at the level of significance ( a ≤ 1.15 ) in the estimates of study sample on the level of internet addiction among ten graders in Aalsharqiya North ,Sultanate Of Oman according to the gender variable in the first,second,fourth,third and sixth measure . However,results have proved the existence of differences in the fifth measure to the males favor.