Abstract: Traditional trade area theory is an effective tool to study business enterprises,especially to study the coverage of retail enterprises.With the development of socialist market economy,however,the concept of trade area should not be applied only to sever the single retail enterprise;it should be regarded as the gathering of enterprises within certain space.With the gathering occurs competition within trade area and among trade areas,which deeply influences the time and space dynamicity within the trade area.Trade area not only changes with economic periods,seasons and life cycles,but also changes dynamically with various inner and outer spatial factors.

Key words: trade area, time dynamicity, spatial dynamicity