I am Nicaraguan living in taiwan. I just need to tranfer in Shanghai Do i need a transit visa?

No, you don't need a visa if your stay in China will be under 24 hours, but keep in mind that Chinese officials look at scheduled time of your flight arrival in China and also at scheduled time of your departure from China. This is very important to know because people sometimes think that if they perform the border formalities before 24 hours of their stay in China, usually at the airport, that they are fine. This is wrong because the only valid details are the times of scheduled arrivals and departures. If the above mentioned is within 24 hours, you are qualified for 24 hours TWOV.