The invention discloses method and system for obtaining capacity of dispatch (CoD) for up going link packet in high speed (UGLPHS), as well as method and device for obtaining effective data rate (EDR) of link. The invention solves defect that the current technique gives out estimated system capacity not accorded with practical situation (PS) since considering system layer only. Based on code rate in physical layer, modulated encoding method, and spread spectrum factor, and number of channel, the method determines EDR of link under different fast mixed automatic retransmission (FMAR) modes. Based on residual frame error rate of system, the method determines SNR threshold of codes, and obtains coincidence relation between EDR of system and SNR of codes. Using EDR of link obtains capacity of system. Analyzing influence on CoD for UGLPHS caused by link adaptive, FMAR, and fast dispatch in system layer synthetically, the invention gives out estimated result accorded with PS relevantly.