Authorities are planning to increase the number of police officers over the next five years.
For every 10,000 permanent residents in the city there are 26 police officers, but that figure will jump to 30 by 2009, according to an official from the Minhang District Public Security Bureau.
The official, who asked not to be identified, said the high crime rate among migrants is a major problem.
"Migrant crime has been increasing steadily since the open policy was adopted," he said.
The migrant crime rate began to rise in the early 1980s with the peak coming in 1998 when migrants were responsible for 80 percent of all crimes in the city, he said.
At that point, the percentage started to decrease. By 2002 the rate was only 45 percent of the total - the lowest ever.
However, 2003 witnessed a new surge, with more than 60 percent of crimes committed by migrants.
Zhang Zongqi, director of Minhang District Public Security Bureau, said the situation is worse in his district. He said about 80 percent of all crimes in Minhang are committed by migrants.
In the first 10 months of this year, there was an average of 600 emergency calls per day in the district, twice as many as the same period last year.
Zhang said the number of registered migrants in Minhang is 770,000, equal to the population of permanent residents.
"Considering many migrants do not register with the police, the number has definitely surpassed the local population," the director added.
Officials said the high crime rate in the district was for two reasons.
First, Minhang lies in an area between the city and the countryside.
Second, the district's booming economy has attracted many enterprises, increasing the demand for manpower.
Minhang police however are trying a new solution to deal with the officer shortage.
"Police assistants are employed to go on patrol with regular policemen, strengthening the police force at night," Zhang said. He admitted it was expedient to depend on police assistants.
"To ensure public security, we need more regular police officers," he said.