In this study, a reaction process for the asymmetric hydrogenation of acetophenone was developed using a T-shaped micro/milli-reactor and a homogeneous catalyst, (5)-RUCY (R) (RuCI[(5)-daipenall(5)-xylbinap]). The results clarified the following points: 1) it is important to separately supply the catalyst and the raw materials to the reactor in order to avoid decreasing the conversion during continuous operation of the process, 2) the micro/milli-reactor can increase the transfer rate of hydrogen to the liquid phase, compared with conventional batch reactors with forced stirring. The reaction time of the micro/milli-reactor required to complete the reaction is several seconds, corresponding to one hundredth of that in the batch reactor, and 3) by adjusting the channel size and flow rate, an increase in the production volume of a single reactor is examined, and the productivity when using four single reactors obtained as a result is comparable to the production on an industrial scale.