Selling a patented product on Taobao, but I didn't know it was patented before. Is it infringement if it is not sold?

Yes, according to Article 1 1 of the Patent Law, you promise to sell, so you infringe, but it is estimated that you are not liable for compensation, because the tort compensation is determined by actual loss or unjust enrichment. Because you only promised to sell and did not cause losses to the other party, there is no need to compensate, there is no unjust enrichment, and the possibility of compensation is relatively small. However, due to your promise to sell, if the order is reduced or stopped, the obligee may be liable for compensation, but it is impossible to estimate the compensation in actual operation, and even if it is compensated, the cost is not great-