Budding yeast (Saccharomyces cerevisiae) protein kinase Sch9 is homologous to the mammalian kinase S6K1. S6K1 is a substrate of mammalian target of rapamycin (mTOR) and phosphatidylinositol-3 kinase (PI3K) and relates to many diseases, including obesity, diabetes and cancer. Both Sch9 and S6K1 are important to the regulation of cell growth in response to different nutrient and stress factors. The residue T570 is a conserved phosphorylation site in the activation loop of Sch9, also called PDK1 site. Whereas another conserved phosphorylation site, T737, in the hydrophobic motif of C terminus is called PDK2 site. The phosphorylation of these two sites are important to Sch9 kinase activity. Upstream kinases Pkh1/2 phosphorylate the PDK1 site, while the Target of Rapamycin Complex 1 (TORC1) phosphorylates the PDK2 site. To better understand the intracellular function of protein kinase Sch9, it is important to elucidate the dynamics and regulation of the phosphorylation of PDK1 and PDK2 sites in Sch9 under different environmental condition. Using antibody that is specific for T570 site phosphorylated Sch9 or T737 site phosphorylated Sch9, we studied the regulation of the phosphorylation of PDK1 and PDK2 sites in Sch9 under different environmental factors and during chronological aging. Our results demonstrate the regulatory model of the phosphorylation of PDK1 and PDK2 sites in Sch9 during nutrient sensing, stress response, calorie restriction and chronological aging. The results also suggest a novel mechanism by which calorie restriction extends chronological lifespan that involves the regulation of the phosphorylation of Sch9 PDK1 site.