A capillary electrochromatography-electrospray-time of flight/mass spectrometric（CEC-ESI-TOF/MS） method for the separation and analysis of chiral drugs mixture of isoprenaline hydrochloride and clorprenaline hydrochloride was established.A home made organic-inorganic hybrid open column was used as chromatographic separation column.The influences of separation and detection conditions including buffer concentration,pH value,operation voltage,separation temperature,sheath fluid type,sheath fluid additives and flow rate of the sheath fluid on resolution and ionization intensity were investigated.The results showed that the baseline separation of four components of two chiral drugs mixture were achieved within 18.5 min under the optimized conditions.