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Ice plays a critical role in chemical evolution during star formation. Complex organic molecules, which have become frequently detected in Class 0/I protostars, form on ice mantles and desorb into gas-phase when the temperature increases. However, the formation pathways of COMs and whether most protostars undergo similar chemical evolution remain open questions with little observational constraints. Most COMs form in the ice mantles covering dust grains. While ALMA provides sub-100 au resolution for studying gaseous COMs in nearby embedded protostars, measurements of the chemical composition in ices had been limited by low-resolution and limited sensitivity until JWST, which can probe ices at a spatial scale comparable to that by ALMA with unprecedented sensitivity. In this talk, I will overview the role of ice in the chemical evolution of star formation as well as the formation pathways of COMs. I will discuss the recent JWST results on ice in protostellar environments, especially focusing on the latest results of the CORINOS and IceAge program. I will also discuss the prospects of ice chemistry in the era of JWST.