There are basically two fundamental problems regarding calcium dynamics in cardiac myocytes. One is the calcium release and the other is the calcium propagation. The first problem is related to the local calcium dynamics and occurs in a very small area called dyads that consist of cell (or T-tubular) membrane, junctional sarcoplasmic reticulum (jSR) membrane, and associated channels (proteins). Due to the very small number of calcium ions existing in this area, the stochastic methods have been proved to be more appropriate for this particular problem. On the other hand, the calcium propagation is effective at the cell-wide level, hence the PDE-based deterministic approaches are used to model how calcium concentration dynamically changes inside the cell and causes the cell contraction. I will give some background on the modeling problems and talk about the previous work on how to tackle these two problems using both stochastic and deterministic approaches.