With the industrialization of Shanghai came a large class of factory workers, in 1930 numbering around ten percent of the city's population of almost three million. The factory workers were primarily drawn from the poor, rural population of the provinces bordering Shanghai. They moved to the city in hope of a better life than they had in the countryside. War and grinding poverty meant that the choice was simply between moving to Shanghai and dying of starvation.

Once in Shanghai, they were employed at the factories, something that usually involved swearing loyalty to fraternities or sororities and at the very least included bribes to foremen, gate guards or recruiters at the factories.

Factory life was tough with long workdays, as much as twelve hours, often on a night shift. Work itself consisted of carrying, sorting or working with machinery that wasn't shielded to protect against workplace injuries, usually in unventilated halls. Work proceeded under the supervision of multiple layers of foremen, along with guards hired from The Green Gang or other criminal enterprises.

Outside working hours, workers lived in either the factory dormitories or in slums practically only consisting of strawhuts and shacks build out of the boats used to reach the city. In the half of the day without work, workers had to sleep, look after their families and secure food for the next day. If enough work could be found, everybody was employed, men, women and children.

Despite the tough conditions, there were still differences among the workers. Natives and migrants from the regions south of the Yangtze were usually given physically less demanding, better paid work and usually lived in permanent housing in the Chinese district of Zhabei or the concessions. Workers could also secure better positions for themselves as foremen, gate guards or similar if they joined the gangsters of The Green Gang and were found useful to them. A large number of the migrants attempting to join the industrial workforce in Shanghai didn't make it and instead had to support themselves through begging, peddling of whatever they could get their hands on, prostitution or similar tasks.