An approximate analytical solution is obtained of the problem of stress-strain state
of a thick-walled sphere from shape memory alloy (SMA), with austenite initial state undergoes direct martensitic phase transformation under the action of a uniform internal or external pressure. The analogous martensite inelasticity problem is solved as well for the case of total twinned martensite initial state of SMA. In the solution we neglect thermo-elastic strains compared to phase and structure strains. For solution the phase transformation problems
we propose that martensite volume part parameter has uniform distribution in material.