小升初

xiǎo shēng chū

progression from elementary school to junior high (abbr. for 小學生升入初中生|小学生升入初中生[xiao3 xue2 sheng1 sheng1 ru4 chu1 zhong1 sheng1])

小

xiǎo

small

升

shēng

to ascend; to rise (variant of 升[sheng1])

初

chū

at first