As a usa passport holder in Spain, how do i apply for China visitor visa

You can apply for it at the CVASC branch in Madrid. First you should submit some basic materials including passport, a photocopy of the passport, an application form attached with your recently-taken photo, proof of legal stay or residence status, as well as air ticket booking record (round trip) and proof of a hotel reservation. And then wait for the result. If it is passed, you can obtain an L type.