Suction caissons have been widely used as anchors and foundations for floating and fixed offshore platforms.The pull-out performance of conventional suction caissons (with upright walls) has been investigated by a number of researchers.However,no attention has been paid to tapered suction caissons.This paper deals with the performance of tapered suction caissons under vertical pull-out loads.A numerical approach is used for this purpose.The numerical model is first verified against test data available for common upright caissons.The verified model is then used to study the pull-out performance of tapered suction caissons.It is noticed that the pull-out capacities exhibited by tapered suction caissons are in general considerably higher than those from their corresponding traditional upright caissons.To obtain an insight into this superior behaviour,effects from certain soil/caisson/drainage parameters on the pull-out capacity of tapered suction caissons are studied.Soil cohesion is noticed to have a linear improving effect on the capacity of both upright and tapered suction caissons.The soil internal friction angle is noticed to have an exponential increasing effect on the pull-out capacity.With a constant caisson diameter,an increase in the aspect ratio is seen to particularly influence the pull-out capacity.With a constant caisson length,an increase in the aspect ratio is discovered to result in non-linear decrease in the pull-out capacity.Under undrained conditions,tapered models generally show less sensitivity to above mentioned soil/caisson parameters as compared with those under drained conditions. Suction caissons have been widely used as anchors and foundations for floating and fixed offshore platforms. The pull-out performance of conventional suction caissons (with upright walls) has been investigated by a number of researchers. However, no attention has been paid to tapered suction The paper deals with the performance of tapered suction caissons under vertical pull-out load. A numerical approach is used for this purpose. Numerical models are first verified against test data available for common upright caissons. The verified model is then used to study the pull-out performance of tapered suction caissons.It is not not that that pull-out- rated exhibited by tapered suction caissons are in generalistant higher than those from their corresponding traditional upright caissons.To obtain an insight into this superior behavior, effects from certain soil / caisson / drainage parameters on the pull-out capacity of tapered suction caissons are studied.Soil cohesion is noti ced to have a linear improving effect on the capacity of both upright and tapered suction caissons. soil internal friction angle is noticed to have an exponential increasing effect on the pull-out capacity .With a constant caisson diameter, an increase in the aspect ratio is seen to be particularly influential in the pull-out capacity. With a constant caisson length, an increase in the aspect ratio is discovered to result in non-linear decrease in the pull-out capacity. Underrain conditions above mentioned soil / caisson parameters as compared with those under drained conditions.