Traditional well log determines the geological and geophysical data of the wellbore and formation fluids properties like porosity, permeability, saturation, resistivity and shale volume. All these are measured during exploration and development stages of a drilling hole. During production or injection of a well, several problems like lost circulation, production tubing integrity and such others need to be known which are very important. Production logging determines wellbore fluid flowing data during production of oil, gas or water. Production problems determination and the remedy of the problems are designed based on production logging. Several production logging tools are used to determine the flow behavior of the formation fluids as well as identification of the top of cement. For multi-layers reservoir, perforation is essential for producing oil or gas from several layers. Production log determines the location of perforation. Spinner flow meter is used to determine the formation fluids velocity whereas Gradiomanometer is for fluids density. Besides, individual sensors are used in production logging for appraisement of various properties. This paper provides a technical review on production logging and its tools along with the modification for horizontal well. The result of this study will help to understand the importance and technique of production log very effectively.