Abstract: In this study, artificial induction of testicular development and maturation in male marble eels was carried out by muscular injection of HCG ( 6 weekly injection of HCG at a dose of 500 U/kg per body weight) and the rate of sexual maturation reached 80.0%. The long diameter and the short diameter of the spermic head was （3.81±0.69）μm, and （1.24±0.15）μm, respectively. The length of the spermic tail was （24.83±3.05） μm. The pH value of sperm was 7.3-7.5. The density of spermatozoa from marble eels was 1.02×10¹⁰ ind/mL. The range of suitable salinity was 15-20, when the salinity of water was 15, the spermatozoa had the best motility, and the spermatozoa had the longest life. The suitable pH of spermatozoa was 6.0-8.0, high or low pH value could restrain the mobility and shortened the longevity. The trends that affected the spermatozoa mobility and life span were almost consistent by four kinds of metallic ions (Mg²⁺, Ca²⁺, Na⁺, and K⁺). When the concentration of solution was too low or too high, the spermatozoa mobility was restrained, and the spermatozoa quick movement time and life span were shortened. When the concentration of MgCl₂, CaCl₂, KCl, and NaCl solutions were 0.4-0.6 g/mL, the spermatozoa mobility was the best, and the highest initiated rate of the spermatozoa reached 41.0%-60.0%.