Using sodium hypophosphite as reducing agent, bath composition and plating condition of electroless copper plating on plating rate have been studied. The followings were determined as optimum, bath composition; $CuSO_4;0.025M,;NiSO_4;0.002M,;NaH_2PO_2;0.4M$, sodium citrate 0.06M, $H_3BO_3$ 0.6M, thiourea or 2-MBT $0.2mg/{ell}$, and operation conditions; pH $9{sim}10$ at bath temperature rage of $60{sim}70^{circ}C$. A small amount of nickel ion($Ni^{2+}/Cu^{2+}$=0.002/0.025) to the hypophosphite reduced solution promotes autocatalysis and continuous plating. An additive such as thiourea or 2-MBT of a small amount($0.2mg/{ell}$) can be used to stabilize the solution without changing plating rate much. The attivation energy between $20^{circ}C;and;70^{circ}C$ were calculated to be 11.3kcal/mol for deposition weight. Plating reaction had been ceased by the adjustment of pH above 13, temperature higher than $90^{circ}C;and;under;20^{circ}C$. Deposited surface became worse in the case of increment of bath temperature above $80^{circ}C$.