Context : Hot subdwarfs are core-helium-burning stars with extremely thin envelopes . We discuss the formation and evolution of hot subdwarfs formed through the stable Roche lobe overflow ( RLOF ) channel of intermediate-mass binaries , although their formation channels are various . Aims : In this study , we concentrate on the formation and evolution of hot subdwarfs binaries through the stable RLOF channel of intermediate-mass binaries . We aim at setting out the properties of hot subdwarfs and their progenitors , so that we can understand the formation and evolution of hot subdwarfs . Methods : Employing Eggleton ^ { \prime } s stellar evolution code , we have computed conservative and nonconservative population I binary evolution sequences . The initial mass of the primary ranges from 2.2 to 6.3 M _ { \odot } , spaced by approximately 0.1 in log M , the initial mass ratio q _ { i } = M _ { 1 } / M _ { 2 } is between 1.1 and 4.5 , and the Roche lobe overflow begins at the main sequence , the Hertzsprung gap and the first giant branch . In nonconservative binary evolution , we assume that 50 percent of the mass lost from the primary leaves the system , carrying away the specific angular momentum of the primary , and the remaining mass is accreted on to the secondary during the RLOF . Also , we have studied the distributions of the mass and orbital periods of hot subdwarfs using the population synthesis approach . Results : We have obtained the ranges of the initial parameters of progenitor binaries and the properties of hot subdwarfs through the stable RLOF channel of intermediate-mass binaries , e.g . mass , envelope mass and age of hot subdwarfs . We have found that hot subdwarfs could be formed through stable Roche lobe overflow at the main sequence and Hertzsprung gap . We have also found that some subdwarf B or OB stars have anomalously high mass ( \sim 1 M _ { \odot } ) with a thick envelope ( \sim 0.07 M _ { \odot } - \sim 0.16 ) in our models . By comparing our theoretical results with observations on the hot subdwarfs in open clusters , we suggest that more hot subdwarfs in binary systems might be found in open clusters in the future . Conclusions :