How can i get the business visa to China?

You may just apply for a China visa to China to make an ivestigation and find a proper partner produing the machineries you need first. Then, you may apply for a China business visa the next time when you go to China to do business with your partner. You can't get the business visa now if you haven't a cooperator in China, since the invitation letter of a duly authorized Chinese Unit or confirmation of invitation is necessary for this kind of China visa application.