Based on the results of observations, that the level of absenteeism is still low, employee absences continue to increase every year, especially for the criteria for absences, sick, late and going home. This shows that the leadership is less than optimal in supervising its employees, it is found that there are still many employees who do not come to work due to permits, illness and are late for work and even go home early. Based on the Government Regulation of the Republic of Indonesia Number 53 of 2010 concerning Discipline of Civil Servants Article 3 Point 11 which states that entering work and obeying the provisions of working hours. As a result, employees do not complete the work and often make mistakes over and over again. The purpose of this study in general is to analyze and describe the significant direct or indirect positive influence of leadership style, supervision and organizational culture on employee performance through motivation as an intervening variable. The research method used is to use path analysis (Part Analysis) to determine the direct or indirect effect of the variables studied. It is then used to analyze the extent to which the work motivation variable is able to mediate an increase in the quality of management information systems to improve employee performance and to what extent the work motivation variable is able to mediate the effect of leadership style on improving the performance of the Serang Regency Education and Culture Office Employees. The results obtained after the research was carried out were: 1) Based on the calculation results of SPSS v.25 Beta value due to the direct influence of leadership style on performance β = 0.000 the indirect effect of motivational mediating factors on the influence of leadership style on the performance of the employees of the Education and Culture Office of Serang Regency obtained value of β = 0.215. The comparison of the value of direct effect is smaller than the value of indirect effect which causes work motivation to be able to mediate the influence of leadership style on employee performance. 2). Based on the calculation results of SPSS v.25 Beta value due to the direct influence of supervision on performance β = 0.155. the indirect effect of the mediating motivational factor on the influence of supervision on the performance of the employees of the Department of Education and Culture of Serang Regency obtained the value of β = -0.046. Comparison of the value of direct effect is greater than the value of indirect effect which causes motivation to be unable to mediate the effect of supervision on employee performance. 3). Based on the calculation results of SPSS v.25 Beta value due to the direct influence of organizational culture on performance β = 0.000. the indirect effect of the mediating motivational factor on the influence of organizational culture on the performance of the employees of the Department of Education and Culture of Serang Regency obtained the value of β = 0.243. Comparison of values direct effect is smaller than value indirect effect that causes motivation to be able to mediate the influence of organizational culture on employee performance.