Abstract: Water samples (N= 96) were collected from Meenachil river for 16 locations (S1-S16) in pre monsoon (PRM), monsoon (MON) and post monsoon (POM) seasons during 2013 and 2014. The nutrients like NO3, PO4 (<1 mg/L) and SiO2 (<4 mg/L) are generally low in the river, and increases from upstream to downstream. The cations of abundance include Na> Ca> K> Mg> Fe for PRM, Ca> Na> Mg> K> Fe for MON and Na> Ca> Mg> K> Fe for POM. Anion abundance include Cl>HCO3>SO4>SiO2>NO3>NO2>PO4 during PRM, HCO3> Cl> SO4> SiO2> NO3> PO4> NO2 during MON and Cl> HCO3> SO4> NO3> SiO2> NO2> PO4 during POM. The factor analysis result illustrate F1 loading (TEMP, TH, SAL, Mg, Ca, SO4, Na, K, Cl and HCO3) of 69.85 % during PRM clearly indicating the role of tropical weathering process in the river system.