The distribution of complexes of sodium picrate and potassium picrate with poly[(benzo-15-crown-5)maleimide], poly[(benzo-15-crown-5)maleimide-alt-alpha-methylstyrene] and benzo-15-crown-5 (b15/5) between water and CH2Cl2 was investigated. Concentration of Na-ion with homopolymer in CH2Cl2 was 52%, while the concentration of complex of alternating copolymer and b15/5 with Na-ion was 22% and 20% respectively. Concentration of K-ion complex in CH2Cl2 with homopolymer and alternating copolymer was 90% and with b15/5 the concentration of complex was 40%. The large difference in the complexation ability of Na-ion and K-ion with homopolymer and alternating copolymer is considered to be the consequence of the formation of 1:1 complex with Na-ion and 2:1 complex with K-ion.