Abstract: Detailed analysis and discussion are made based on the kinetics and dynamics of chain drive in the following aspects relating to tooth shape: chain disengagement,impact,bending strength and contact strength of sprockets,pitch tolerance and interference on mating of rollers.A theoretical tooth shape equation of the sprocket is derived,and an equation relating design parameters to the tooth shape is obtained also.Starting from the existing problems of sleeve roller chain sprockets used in oil fields a new tooth shape of three curved sections(tooth ditch,working section,and tooth top transition section)and one straight section(tooth top)is proposed.This tooth shape will result in less impact,less contact stress and less component causing disengagement,and accommodates a variety of working conditions.Optimal design has been made on different working conditions(high speed and light load,low speed and heavy load,high speed andheavy load).Examples are given also.