Thermoelectric materials provide an alternative route for refrigeration and power generation bydirect conversion between thermal and electrical energy. With high chemical stability andextraordinary high thermoelectric performance (ZT figure of merit is 1 at 1000K) at hightemperatures, Ca3Co4O9 is a promising candidate over the other intermetallic thermoelectriccompounds. However, the mechanism of high thermoelectric performance of this compound is notwell understood. We have sucessfully synthesized high quality polycrystalline powder ofCa3Co4O9 and conducted magnetization measurements between 4K-1000K. We observed manyinteresting magnetic states especially at high temps. Crystal and magnetic structure analysis andprecise measurements of internal bond-lengths and bond-angles as function of temperaturewould reveal strong correlations with the observed physical properties.