The theoretical investigations on the effect of different plasmas on the growth and field emission properties of a spherical carbon nanotube (CNT) tip placed over cylindrical CNT surfaces have been carried out for the typical glow discharge plasma parameters. Different plasmas such as H 2 , Ar, CH 4 and CF 4 have been considered, and the growth of the CNT in the presence of various plasmas has been estimated in the present investigation. This study suggests that the field emission from the CNT grown in the presence of the H 2 plasma is largest. It is also found that amongst the plasmas considered, the CF 4 plasma is the most favourable for the growth of the large radius CNT, since the radius achieved in the CF 4 plasma is the largest.