The present invention relates to a medicinal water-soluble antifungal macromolecular compound used for treating infectious diseases, especially, relates to a poly-conjugate which includes an active drug substance and a macro-molecular polymer which are combined with each other through chemical bonds. The active drug substance is a polyene macrolide compound such as amphotericin B. Also provided are a method of preparing the poly-conjugate, a method for increasing solubility of the active drug substance and a method for treating fungal infection, which is any disease related to fungus, such as sepsis, endocarditis, meningitis (caused by cryptococcus and other fungus), abdominal infection (including those related to dialysis), pulmonary infection, urinary tract infection and the like. The poly-conjugate has excellent properties in biological performance and/or physical performance and/or chemical performance.
