This research examined the differences in the level of parental motivational practices which includes: (involvement, encouragement, expectations, autonomy) that due to the variable type, academic achievement, and economical state of the parental, to know the significance correlation between parental motivational practices and academic achievement, a better knowledge of dimensional influential in academic achievement, and predictability of academic achievement known of Parental Motivational Practices on a sample consisted of 400 students from eleventh grade in the Province of South Batinah in Sultanate of Oman, by using a scale of parental motivational practices prepared by researcher, a measure of the economical state prepared by (alhashemia, 2009) and the transcript from issued by the General Directorate of Education in South Batinah of Oman(2012/ 2013). The result significant that there aren't any differences of encouragement for both the parents due to the kind, there are differences of expectations and autonomy of both parents in favor of females, there are differences of involvement for father of favor of males, and for mothers, of favor of females. There aren't any differences of involvement, there are differences of other parental motivational practices dimensions for both the parents due to the academic achievement beneficial to high academic achievement. There aren't any differences of involvement, there are differences of other parental motivational practices dimensions of for both the parents due to the economical state of the parental beneficial to high economical state of the parental. There are correlation statistically significant between the dimensions of practices motivation following: (encouragement, expectations, autonomy) for both parents, and academic achievement, and there are any correlation statistically significant between the father's involvement and academic achievement, there are a correlation statistically significant between the mother's involvement and academic achievement. Also, The result significant that the autonomy is the best dimensions of father's motivational practices influential in the academic achievement, while the involvement is the best dimensions motivational practices for mothers influential in the academic achievement of the eleventh grade students. Unpredictable collection of study known of all dimensions beneficial to the following: (involvement, encouragement, expectations, autonomy) for both parents, and ended discuss the study findings and recommendations.