Abstract: Epistylis galea Ehrenberg,1831,was collectedfrom an eutrophic freshwater pond near Harbin,China,fromApril to October in 2002.By living and protargol-impregnated specimens,the morphology,infraciliature and myonemic system was studied.Living observations were carried out using both bright field and differential interference contrast microscopy. Protargol stainingwas done according to the method modified by Shi &Frankel(1990)to reveal the infraciliature and myonemic systemof the organism.Drawings were made with the help of the camera lucida.Epistylis galea,a colony infresh water which has a colonial stalk with two branches,of which the last branch is shortest andis significant metamerism between each of myofilament after impregnated by protargol. Its whole body is relatively soft and highlytransparency;while looks like a cone when it uphold completely. Asfor life morphology zooids are reasonable stout and relativelyconstant in shape,length in vivo is 200-300 μm,width is 70-90 μm,and the widest area are at the peristomial lip(PL)of the organism. The peristomial disc(PD)is significantly elevated when the cell is completely extending. Contractiel vacuole is onlyone,relatively big at top of the cell. Most of the cell organelles are located at the upper 2/3 of organism,such as the vestibulum(in fundibulumor buccal cavity),contractile vacuole(CV),macronucleus(Ma),micronucleus(Mi) and food vacuole(FV) ;the other1/3 of cell,however,is spacious and rather highly transparency,there are lots of longitudinal figure streaks. The macronucleus(Ma)is “ J” shape,longitudinal originates the middle of peristomial lip(PL),transverse along the organism extend to aboral wreathof cilia(ACW) ;while macronucleus by protargol impregnated located at the upper of ACW,the funnel is rather wide. Cytopharynx(Cph),which has been used protargol impregnated,is spindle shape,originates cell’ s fore head and reach constantly ACW.The haplokinety(HK)and the polykinety(PK)are parallel with each other from the peak of cell,making approximately about1.5 turns around the PD in a counter clockwise direction,then they separate. There are three infundibular polykineties(P1— P3),each of which consists of 3 rows of kinetosomes. P1and P2originate from the end of PK,P2converges with P1and P3at the abstomal terminal of P3. After P1and P3confluenced,P1terminate at once,but P3continue in bracklet shaped bend;after germinalrow of kineties terminating,haplokinety becomes two columns of kineties which parallel with filamentous reticulum;both of themterminate at the same area. Compared with P1and P2,P3 is significantly short. HKconsists of two kinetosomes and lies on theside of the infundibulum opposite to the PK.The filamentous reticulum(FR),paraller with HK,is “S” shape and considerable bright. Germinal row lies beyond the HK.Cytopharynx(Cph)is relatively figure and bright,extend approximately 2/3 of the length of the organisum.The myonemal system is composed of two kinds of fibers:the longitudinal fibbers(LF) and peristomial disc fibbers(PDF).LF and PDF connect with each other and become one robust fiber net,which converged the whole organisum,comprising approxi mately 80 bands. Some LF branchs originate from HK and directly connect with PDF;while the others,which extend the wholelength of LF,connect with each other,and then joining another LFπsfibbers during extending. The PDF is unique. Parts of longi tudinal fibber originate haplokinety,and directly connect with the peristomial disc(PD). The situation is “Y” -shape fibber,thelongitudinal fibber constantly extend the whole body and connect with each other and became one reticular fibber system,someshrink intensely longitudinal fibber more and more roughness and become a netlike. Slight shrinking,however,has no this phe-nomena,the total of longitudinal fiber became one fummel like network,the peristomal disc,like the shape of plate,is not spaciousand stride network,yet at the entrance is rather few and scattered.In brief,we conclude that its infraciliature and myonemic system reveals the following characteristics:(i)one contractal vacuole 21-25 μm,in upset of midbody region both the nuclear and the other oranelles situate in the cytoplasm which locatesabove the 2/3 part of the individual ;(ii)LF and PDF connect directlywith eachother and become one robust fibre net. (iii)threeinfudibular polykineties(P1— P3)consist of 3 rows of kinetosomes;(iv) P1terminates near the 2/3 length of P3,and P3enters intothe beneath of cytopherynx where only observe three rows of P3.