BEIJING - Chinese postal and express service companies saw their revenue up 23.1 percent year-on-year in the first quarter, according to information released by the State Post Bureau on Thursday.

Private express firms' market share continued to grow, with their business volume reaching 85.8 percent in the first quarter, up 4.2 percent year-on-year.

Express service in central and western China showed stronger growth rate of more than 30 percent thanks to the country's strategic policies to support the development of the region.

Meanwhile, express service within cities grew by about 50 percent in business volume and revenue, indicating the sector's structural changes due to more expansive stocking stations and more convenient transportation.