The present invention provides a process and a system for coking and simultaneous upgrading of a heavy hydrocarbon feedstock. More particularly the present invention relates to a process of cracking heavy hydrocarbon feedstock employing high heat carrier, incorporated with weak acid sites for improving the liquid yield and reducing coke yield. The feedstock is vaporized and brought in contact with a heat carrier material to produce a product stream and separating the product stream from the particulate heat carrier, regeneration of the particulate heat carrier to the extent of 10-30% and collecting a gaseous and liquid product from the product stream.