Biological degradation of 2,4,6-trinitrophenol (TNP) by Rhodococcus sp.NJUST16 in mineral salt medium was investigated in shake-flask experiments at pH of 7.0 and 30 degrees C, over a wide range of initial TNP concentration (20-800 mgl(-1)). The TNP was observed to be the inhibitory compound. For the studied concentration range, Haldane's model could be fitted to the growth kinetics data well with the kinetic constants mu(max)=0.2362 h(-1), K(s)=9.9131 mgl(-1) and K(i)=362.7411 mgl(-1). Further, the variation of observed yield coefficient Y with initial TNP concentration and the decay coefficient were investigated. It is our view that the above information would be useful for modeling and designing the units treating TNP-containing wastewaters.