This study aims to improve the competence of teachers in preparing a lesson plan through continuous guidance in SMK 1 Mamuju, West Sulawesi province. Action research school is implemented through two cycles to see an increase in the competence of teachers write eleven components in the lesson plan. In the first cycle (first) all Master (twelve) lists all the components in its lesson plan. In the first cycle, the number of overall score obtained 12 teachers = 759, divided by 11 components in the lesson plan (759/11 = 69), if it were presented was 69%. While on the second cycle (second) All teachers whose number twelve included all the components in its lesson plan. In the second cycle, the number of overall score obtained 12 teachers = 916, divided by 11 components in the lesson plan (916/11 = 83), if it were presented was 83%, which means an increase of 14% from the first cycle. Overall all teachers (12 people) have increased competence in preparing lesson plans, because all the teachers at SMK 1 Mamuju already included all the components in the lesson plan after going through continuous guidance. Data collection techniques in this research are interviewing techniques (interview), observation and discussion. While the tools used in this study were (1) guide the questionnaires to determine the initial ability possessed by teachers about lesson plans, (2) uses observation sheets to determine the components of lesson plans, (3) Discussions for sharing opinions between researchers and teachers.