The study consists of two parts. Study one looked into the effects of tapping frequency and yield stimulation in Hevea rubber and Study two dealt with the effect of tapping system and micro tapping techniques on the growth and yield of fourteen year old RRIM 600 at UUSMARC. Study I shows that the increase or decrease in yield indicates the direct effect of frequency/rate and methods of ethephen stimulation. Study II indicates that tapping systems affected the yield of rubber trees seven years after opening. Puncture tapping gave very poor yield during the first four years of tapping. The increase in yield was the effect of long cut and high frequency tapping plus stimulation.