Mr.Hares, you can't make the application online, you have to submit visa application to visa office of Chinese Embassy in Dhaka in person or entrust someone else to submit it on your behalf. If you want to apply for business visa, you have to have Original Visa Notice Form issued by authorized departments of Chinese Government (the Chinese company you cooperate knows how to apply for it for), otherwise, you can only apply for tourist visa, as for the requirements, please refer to http://bd.china-embassy.org/eng/lsyw/t569035.htm