The purpose of this research are to analyze the effect of (1) the headmaster’s leadership on climate work, (2 the headmaster’s leadership and work climate on achievement motivation, and (3) the headmaster’s leadership, work climate and achievement motivation to discipline SMPN 18 Padan’s teachers. The population was teacher of SMPN 18 Padang are 62 peoples and sample are 51 people with Proportional stratified random sampling method. For the data analysis technique used was path analysis. The result are: headmaster’s leadership influence the climate of work. The headmaster’s leadership, work climate and achievement motivation significantly influence teacher’s discipline. Achievement motivation has the greatest direct influence on discipline teachers compared with the principal's leadership and organizational climate.