E-commerce is a mechanism where business and consumers make transactions directly over the Internet. For forming an online contract, business provides detailed product information online, including product photos, specification and even reviews, by creating web pages to attract customers. However, electronic transactions are different from physical store transactions which customers can actively touch and examine products before they decide to place an order. When online price errors occur, most stores choose not to honor price and orders because of tremendous economic loss caused. Nevertheless, the issues of online price errors are complicated; the issues include whether valid contracts between customers and online stores have been formed when a customer places an order online? Is the detailed web page information a contract offer or just an invitation to offer? Do replies by automated system created by online stores constitute contract acceptances? Are online stores eligible to cancel the contract in case of pricing errors? All these issues need delicately considering the interest balance between business loss and consumer protection.This article focuses on solving above issues by analyzing and comparing seven related Taiwanese court decisions, including well-known Dell price error cases, and referring to international judicial opinions. The conclusion of the comments providing comparison chart of court decisions has found three decisive points by which courts accordingly exercise to make decisions. For avoiding future price error controversy, this article suggests that business should slightly adjust the content of replied mail sent by automated system to verify the validity of the contract. This article concludes that since online business is capable of designing an enforceable system to control its own risk, it is not appropriate for business to shift its price error liability to consumers.