The magnetic system of the pseudobinary compound Mn1-xCoxGe has been studied using small angle neutron scattering and susceptibility measurements. It is found that Mn1-xCoxGe orders magnetically at low temperatures in the whole concentration range of x_c2 [0 - 0:9]. Four different states of the magnetic structure have been found at low temperatures: the long-range ordered (LRO) short period helical magnetic structure at x < xc1 < 0:25, the short-range ordered (SRO) short period helical magnetic structure at xc1 <x < xc2 = 0:45, the long period helical magnetic structure at xc2 < x < 0:8 and the ferromagnetic-like structure at x = 0:9.