  Appreciation of Stochastic Loewner evolution (SLE$_\kappa$), as a powerful
tool to check for conformal invariant properties of geometrical features of
critical systems has been rising. In this paper we use this method to check
conformal invariance in sandpile models. Avalanche frontiers in Abelian
sandpile model (ASM) are numerically shown to be conformally invariant and can
be described by SLE with diffusivity $\kappa=2$. This value is the same as
value obtained for loop erased random walks (LERW). The fractal dimension and
Schramm's formula for left passage probability also suggest the same result. We
also check the same properties for Zhang's sandpile model.
