The incident took place at his home in Kyaukume in Shan state of Myanmar.
Two unidentified motorcycle borne gunmen attacked the newly elected parliamentarian Htike Zaw and fled.
NLD spokesperson Myo Nunt told Reuters that the party has asked the authorities to investigate the incident as soon as possible.
The party also denounced poll violence in Myanmar calling it bad for the future.
The ruling NLD won an emphatic victory in the recently held elections winning 920 seats out of 1,117 contested seats in the Union, state and regional legislatures.
It improved upon its earlier massive tally of 2015 defeating its closest rival Union Solidarity and Development Party (USDP) which is considered to enjoy the support of the military.
The USDP secured 71 seats or 6.4 percent of the total.
The USDP has filed more than 800 complaints to the results announced by the Union Elections Commission disputing the results.
Earlier, USDP had alleged irregularities and mismanagement in the conduct of the elections which have been denied by the UEC.
Report by: Rajesh Jha