Shanghai's older airport Hongqiao (IATA: SHA) offers domestic flights and few international flights. It is composed of two terminals, T1 and T2. T2 is new and beside the Hongqiao Railway Station, the small and old T1 is 2km east to T2 and under the reconstruction now. Now Hongqiao Airport is a part of the world's largest Hongqiao Transportation Hub, which is consist of airport, bus terminal, railway station, maglev station (not yet ready), metro station and taxi stands. There are many Chinese/English/Japanese/Korean signs inside, the mazy Hongqiao Transportation Hub is still too big and complicated for a foreigner, so don't hesitate to ask the staffs and make sure to reserve enough time to transfer any transportation. The two terminals are linked by terminal shuttle bus (free, 20-min ride, 06:00~22:30, leaves every 30 minutes) or Metro Line 10 (¥3, 3 minutes, T1->T2: 06:18~22:58, T2->T1: 05:56~23:01, interval: every 5~15min).
Hongqiao Airport is served by Metro Lines 2 and 10, Line 2 only serves Terminal 2 and Line 10 serves both T1 and T2. Line 2 goes all the way to Pudong Airport (but have to change train at Guanglan Road station). Metro operates 05:35-22:45 (service to and from Pudong Airport has limited hours).