A detailed resear ch is reported in this pa per on the biolo gy of age, gr ow th, feeding habit, r epr oduct ion o f Odontobutis potamphila ( G..nther ) . The oto lith is the best indicator in ag e de terminat ion, w ith ve rtebra and scale as reference. The pe cto ral r adial bo ne is not re liable in age determinat ion. Of all the aquat ic ca tches the age .. and .. co ntr ibuted 85% o f the to ta l number in f iv e.. ye ar gro ups f rom 0 to ... The radius o f oto lith a nd body length are in a signif icant line ar corr elat ion, w hich ca n be described by the fol low ing equat ion: L = 5. 313 3R - 0. 069 03. The relat ionship between bo dy length and bo dy w eight (W) and net w eig ht (W..) ca n be described by the fo llow ing equat ion: .. W= 0. 022 416L3. 086 7; W..= 0. 024 98L2. 974 7. The f ish mainly feeds on juv enile f ish and shrimps, but on less amo unt o f mo lluscs and insect s. The co urse of o varia n maturat io n can be div ided into six sta ges and .. ~ .. .. o r .. stage. The f ish releases two batches at least in a breeding season. The breeding se ason is betw een March and June. The nest preferences are w idely given to many kinds o f substances, such a s gr ass ro o t, tit le, some and other materia ls. The egg mass can be fo und on the top o r side of the nest . The indiv idual abso lute f ecundity ranges f rom 2 645~ 7 708 eg gs and individua l re lat ive ranges f rom 56~ 163 eggs.