A study using a Laser Precipitation Monitor (LPM) for several rain events spanning the monsoon season of 2013 at Kolkata, India, reflects the effect of velocity measurements on Z-R and A-R relationship for both convective and stratiform events. Laser precipitation monitor measures ground based drop size distribution and drop velocity simultaneously. The presence of high velocity small drops (super-terminal) and low velocity large drops (sub-terminal) is abundantly experienced during different types of rain in the tropical region as observed by a Laser precipitation monitor (LPM). The number fraction of these drops is higher in convective rain than in stratiform rain. As the observed drop velocities show significant variation from the theoretically derived velocities, it is possible to get noticeable difference in rain rate calculations, Z-R and A-R relationships. The study involves a comparison of Z-R and A-R relations using both Gunn-Kinzer (GK) and actual observed velocity in convective and stratiform rain regimes separately as there was significant difference in number fraction of high velocity and low velocity rain drops in both the cases. © 2016 IEEE.