Based on the generalized Huygens-Fresnel principle,the analytical expression of the cross-spectral density function for the partially coherent Laguerre-Gaussian (PCLG) beam propagating in biological tissues is derived,and used to study the effect of propagation distance 〖ＷＴＢＸ〗z,topological charge m,radial index n,and spatial coherence length σ0 on the normalized intensity and phase evolution of the beam in the dermis of mouse tissue.It is shown that as the propagation distance increases,the intensity gradually decreases,the intensity distribution profile slowly evolves from multi-peak shape to single-peak shape.Initial m-order coherence vortex and n circular edge dislocations evolve into m+2n coherent vortices firstly,and then m+2n coherent vortices are newly created.In addition,the larger the topological charge,radial index,and spatial coherence length,the slower the change in the intensity distribution and phase evolution.