Is Liu's calligraphy worth collecting?

Worth it. Liu's calligraphy works are good at cursive script, and also attack regular script, official script and running script. Pay attention to the collocation of font structure and stroke thickness, giving people a dignified and beautiful feeling. Liu also has original opinions on calligraphy theory, including "An Introduction to China's Calligraphy Art" and "Calligraphy Aesthetics", which have also been recognized and praised by some professionals, so Liu's calligraphy works have certain collection value.